Some docs polish

@arturi

website/src/docs/contributing.md

@@ -4,7 +4,7 @@ type: docs
 order: 4
 ---
 
-## Uppy Development
+## Uppy development
 
 Fork the repository into your own account first. See the [GitHub Help](https://help.github.com/articles/fork-a-repo/) article for instructions.
 
@@ -16,7 +16,7 @@ cd uppy
 npm install
 ```
 
-Our website’s examples section is also our playground, please read [Local Previews](#Local-Previews) section to get up and running.
+Our website’s examples section is also our playground, please read the [Local Previews](#Local-Previews) section to get up and running.
 
 ## Tests
 
@@ -24,7 +24,7 @@ Unit tests are using Jest and can be run with:
 
 `npm run test:unit`
 
-For acceptance (or end to end) tests, we use [Webdriverio](http://webdriver.io). For it to run locally, you need to install selenium standalone server, just follow [the guide](http://webdriver.io/guide.html) to do so. You can also install Selenium Standalone server from NPM:
+For acceptance (or end-to-end) tests, we use [Webdriverio](http://webdriver.io). For it to run locally, you need to install a Selenium standalone server. Just follow [the guide](http://webdriver.io/guide.html) to do so. You can also install a Selenium standalone server from NPM:
 
 ```bash
 npm install selenium-standalone -g
@@ -35,30 +35,31 @@ And then launch it:
 
 `selenium-standalone start`
 
-After you’ve installed and launched the selenium standalone server, run:
+After you have installed and launched the selenium standalone server, run:
 
 `npm run test:acceptance:local`
 
 These tests are also run automatically on Travis builds with [SauceLabs](https://saucelabs.com/) cloud service using different OSes.
 
-## Website Development
+## Website development
 
-We keep the [uppy.io](http://uppy.io) website in `./website` so it’s easy to keep docs & code in sync as we’re still iterating at high velocity.
+We keep the [uppy.io](http://uppy.io) website in `./website`, so it’s easy to keep docs and code in sync as we are still iterating at high velocity.
 
 The site is built with [Hexo](http://hexo.io/), and Travis automatically deploys this onto GitHub Pages (it overwrites the `gh-pages` branch with Hexo's build at every change to `master`). The content is written in Markdown and located in `./website/src`. Feel free to fork & hack!
 
-Even though bundled in this repo, the website is regarded as a separate project. So it has its own `package.json` and we aim to keep the surface where the two projects interface as small as possible. `./website/update.js` is called during website builds to inject the Uppy knowledge into the site.
+Even though bundled in this repo, the website is regarded as a separate project. As such, it has its own `package.json` and we aim to keep the surface where the two projects interface as small as possible. `./website/update.js` is called during website builds to inject the Uppy knowledge into the site.
 
-### Local Previews
+### Local previews
 
-It's recommended to exclude `./website/public/` from your editor if you want efficient searches.
+It is recommended to exclude `./website/public/` from your editor if you want efficient searches.
 
 To install the required node modules, type:
+
 ```bash
 npm install && cd website && npm install && cd ..
 ```
 
-For local previews on http://127.0.0.1:4000 type:
+For local previews on http://127.0.0.1:4000, type:
 
 ```bash
 npm start
@@ -66,7 +67,7 @@ npm start
 
 This will watch the website, as well as Uppy, as the examples, and rebuild everything and refresh your browser as files change.
 
-Then, to work on e.g. the XHRUpload example, you'd edit the following files:
+Then, to work on, for instance, the XHRUpload example, you would edit the following files:
 
 ```bash
 atom src/core/Core.js \
@@ -75,13 +76,13 @@ atom src/core/Core.js \
   website/src/examples/xhrupload/app.es6
 ```
 
-And open <http://0.0.0.0:4000/examples/xhrupload/> in your webbrowser.
+And open <http://0.0.0.0:4000/examples/xhrupload/> in your web browser.
 
-## CSS Guidelines
+## CSS guidelines
 
-The CSS standards followed in this project closely resemble those from [Medium's CSS Guidelines](https://gist.github.com/fat/a47b882eb5f84293c4ed). If it's not mentioned here, follow their guidelines.
+The CSS standards followed in this project closely resemble those from [Medium's CSS Guidelines](https://gist.github.com/fat/a47b882eb5f84293c4ed). If something is not mentioned here, follow their guidelines.
 
-### Naming Conventions
+### Naming conventions
 
 This project uses naming conventions adopted from the SUIT CSS framework.
 [Read about them here](https://github.com/suitcss/suit/blob/master/doc/naming-conventions.md).
@@ -118,7 +119,7 @@ Syntax: [<namespace>-]<ComponentName>[-descendentName][--modifierName]
 
 ### SASS
 
-This project uses SASS, with some limitations on nesting.  One-level deep nesting is allowed, but nesting may not extend a selector by using the `&` operator.  For example:
+This project uses SASS, with some limitations on nesting.  One-level-deep nesting is allowed, but nesting may not extend a selector by using the `&` operator.  For example:
 
 ```sass
 /* BAD */
@@ -138,11 +139,11 @@ This project uses SASS, with some limitations on nesting.  One-level deep nestin
 }
 ```
 
-### Mobile-first Responsive Approach
+### Mobile-first responsive approach
 
 Style to the mobile breakpoint with your selectors, then use `min-width` media queries to add any styles to the tablet or desktop breakpoints.
 
-### Selector, Rule Ordering
+### Selector, rule ordering
 
 - All selectors are sorted alphabetically and by type.
 - HTML elements go above classes and IDs in a file.