Some docs polish

@arturi

website/src/docs/aws-s3.md

@@ -7,7 +7,7 @@ permalink: docs/aws-s3/
 ---
 
 The `@uppy/aws-s3` plugin can be used to upload files directly to an S3 bucket.
-Uploads can be signed using [Uppy Server][uppy-server docs] or a custom signing function.
+Uploads can be signed using either [Uppy Server][uppy-server docs] or a custom signing function.
 
 ```js
 const AwsS3 = require('@uppy/aws-s3')
@@ -20,14 +20,16 @@ uppy.use(AwsS3, {
 })
 ```
 
-There are broadly two ways to upload to S3 in a browser. A server can generate a presigned URL for a [PUT upload](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPUT.html), or a server can generate form data for a [POST upload](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html). uppy-server uses a POST upload. See [POST uPloads](#post-uploads) for some caveats if you would like to use POST uploads without uppy-server. See [Generating a presigned upload URL server-side](#example-presigned-url) for an example of a PUT upload.
+There are broadly two ways of uploading to S3 in a browser. A server can generate a presigned URL for a [PUT upload](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPUT.html), or a server can generate form data for a [POST upload](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html). Uppy-server uses a POST upload. See [POST Uploads](#post-uploads) for some caveats if you would like to use POST uploads without uppy-server. See [Generating a presigned upload URL server-side](#example-presigned-url) for an example of a PUT upload.
 
-There is also a separate plugin for S3 Multipart uploads. Multipart in this sense is Amazon's proprietary chunked, resumable upload mechanism for large files. See the [`@uppy/aws-s3-multipart`](/docs/aws-s3-multipart) documentation.
+There is also a separate plugin for S3 Multipart uploads. Multipart in this sense refers to Amazon's proprietary chunked, resumable upload mechanism for large files. See the [`@uppy/aws-s3-multipart`](/docs/aws-s3-multipart) documentation.
 
 ## Installation
 
 This plugin is published as the `@uppy/aws-s3` package.
 
+Install from NPM:
+
 ```shell
 npm install @uppy/aws-s3
 ```
@@ -40,6 +42,8 @@ const AwsS3 = Uppy.AwsS3
 
 ## Options
 
+The `@uppy/aws-s3` plugin has the following configurable options:
+
 ### `id: 'AwsS3'`
 
 A unique identifier for this plugin. Defaults to `'AwsS3'`.
@@ -58,18 +62,18 @@ uppy.use(AwsS3, {
 
 > Note: When using [uppy-server][uppy-server docs] to sign S3 uploads, do not define this option.
 
-A function returning upload parameters for a file.
+A function that returns upload parameters for a file.
 Parameters should be returned as an object, or a Promise for an object, with keys `{ method, url, fields, headers }`.
 
-The `method` field is the HTTP method to use for the upload.
-This should be one of `PUT` or `POST`, depending on the type of upload used.
+The `method` field is the HTTP method to be used for the upload.
+This should be one of either `PUT` or `POST`, depending on the type of upload used.
 
-The `url` field is the URL to send the upload request to.
-When using a presigned PUT upload, this should be the URL to the S3 object including signing parameters in the query string.
+The `url` field is the URL to which the upload request will be sent.
+When using a presigned PUT upload, this should be the URL to the S3 object with signing parameters included in the query string.
 When using a POST upload with a policy document, this should be the root URL of the bucket.
 
 The `fields` field is an object with form fields to send along with the upload request.
-For presigned PUT uploads, this should be empty.
+For presigned PUT uploads, this should be left empty.
 
 The `headers` field is an object with request headers to send along with the upload request.
 
@@ -101,13 +105,13 @@ strings: {
 ## S3 Bucket configuration
 
 S3 buckets do not allow public uploads by default.
-In order to allow Uppy to upload to a bucket directly, its CORS permissions need to be configured.
+In order to allow Uppy to upload directly to a bucket, its CORS permissions need to be configured.
 
 CORS permissions can be found in the [S3 Management Console](https://console.aws.amazon.com/s3/home).
 Click the bucket that will receive the uploads, then go into the "Permissions" tab and select the "CORS configuration" button.
 An XML document will be shown that contains the CORS configuration.
 
-Good practice is to use two CORS rules: one for viewing the uploaded files, and one for uploading files.
+It is good practice to use two CORS rules: one for viewing the uploaded files, and one for uploading files.
 
 Depending on which settings were enabled during bucket creation, AWS S3 may have defined a CORS rule that allows public reading already.
 This rule looks like:
@@ -149,7 +153,7 @@ When using a presigned upload URL, the following permissions must be granted:
 <AllowedMethod>PUT</AllowedMethod>
 ```
 
-The final configuration should look something like the below:
+The final configuration should look something like this:
 
 ```xml
 <?xml version="1.0" encoding="UTF-8"?>
@@ -174,7 +178,7 @@ The final configuration should look something like the below:
 
 In-depth documentation about CORS rules is available on the [AWS documentation site](https://docs.aws.amazon.com/AmazonS3/latest/dev/cors.html).
 
-## POST Uploads
+## POST uploads
 
 uppy-server uses POST uploads by default, but you can also use them with your own endpoints. There are a few things to be aware of when doing so:
 
@@ -190,9 +194,9 @@ uppy-server uses POST uploads by default, but you can also use them with your ow
    })
    ```
 
-## S3 Alternatives
+## S3 alternatives
 
-Many other object storage providers have an identical API to S3, so you can use the `@uppy/aws-s3` plugin with them. To use them with Uppy Server, you can set the `UPPYSERVER_AWS_ENDPOINT` variable to the endpoint of your preferred service.
+Many other object storage providers have an identical API to S3, so you can use the `@uppy/aws-s3` plugin with them as well. To use them with Uppy Server, you can set the `UPPYSERVER_AWS_ENDPOINT` variable to the endpoint of your preferred service.
 
 ### DigitalOcean Spaces
 
@@ -209,7 +213,7 @@ For a working example that you can run and play around with, see the [digitaloce
 
 ### Google Cloud Storage
 
-For Google Cloud Storage, you need to take a few more steps. For the `@uppy/aws-s3` plugin to be able to upload to a GCS bucket, it needs the Interoperability setting enabled. You can enable the Interoperability setting and [generate interoperable storage access keys](https://cloud.google.com/storage/docs/migrating#keys) by going to [Google Cloud Storage](https://console.cloud.google.com/storage) » Settings » Interoperability. Then set the environment variables for Uppy Server like below:
+For Google Cloud Storage, you need to take a few more steps. For the `@uppy/aws-s3` plugin to be able to upload to a GCS bucket, it needs the Interoperability setting enabled. You can enable the Interoperability setting and [generate interoperable storage access keys](https://cloud.google.com/storage/docs/migrating#keys) by going to [Google Cloud Storage](https://console.cloud.google.com/storage) » Settings » Interoperability. Then set the environment variables for Uppy Server like this:
 
 ```bash
 export UPPYSERVER_AWS_ENDPOINT="https://storage.googleapis.com"
@@ -220,11 +224,11 @@ export UPPYSERVER_AWS_SECRET="YOUR-GCS-SECRET" # The Secret
 
 You do not need to configure the region with GCS.
 
-You also need to configure CORS differently. Unlike Amazon, Google does not offer a UI for CORS configurations. Instead an HTTP API must be used. If you haven't done this already, see [Configuring CORS on a Bucket](https://cloud.google.com/storage/docs/configuring-cors#Configuring-CORS-on-a-Bucket) in the GCS documentation, or follow the below steps to do it using Google's API playground.
+You also need to configure CORS differently. Unlike Amazon, Google does not offer a UI for CORS configurations. Instead, an HTTP API must be used. If you haven't done this already, see [Configuring CORS on a Bucket](https://cloud.google.com/storage/docs/configuring-cors#Configuring-CORS-on-a-Bucket) in the GCS documentation, or follow the steps below to do it using Google's API playground.
 
-GCS has multiple CORS formats, both XML and JSON. Unfortunately their XML format is different from Amazon's, so we can't simply use the one from the [S3 Bucket configuration](#S3-Bucket-configuration) section. Google appears to favour the JSON format, so we'll use that.
+GCS has multiple CORS formats, both XML and JSON. Unfortunately, their XML format is different from Amazon's, so we can't simply use the one from the [S3 Bucket configuration](#S3-Bucket-configuration) section. Google appears to favour the JSON format, so we will use that.
 
-#### JSON CORS Configuration
+#### JSON CORS configuration
 
 The JSON format consists of an array of CORS configuration objects. An example using POST policy document uploads is shown here:
 
@@ -259,7 +263,7 @@ Otherwise, you can manually apply it through the OAuth playground:
    1. Select the "Cloud Storage JSON API v1" » "devstorage.full_control" scope
    1. Press "Authorize APIs" and allow access
  1. Click "Step 3 - Configure request to API"
- 1. Configure it like below:
+ 1. Configure it as follows:
    - HTTP Method: PATCH
    - Request URI: `https://www.googleapis.com/storage/v1/b/YOUR_BUCKET_NAME`
    - Content-Type: application/json (should be the default)
@@ -309,7 +313,7 @@ See the [aws-presigned-url example in the uppy repository](https://github.com/tr
 
 ### Retrieving presign parameters of the uploaded file
 
-Once the file is uploaded, it's possible to retrieve the parameters that were
+Once the file is uploaded, it is possible to retrieve the parameters that were
 generated in `getUploadParameters(file)` via the `file.meta` field:
 
 ```js