add docs for using contributing locale packs from npm and cdn

Co-Authored-By: Kevin van Zonneveld <kevin@transloadit.com>

website/src/docs/locales.md

@@ -0,0 +1,85 @@
+---
+type: docs
+order: 6
+title: "Locale Packs"
+permalink: docs/locales/
+category: 'Docs'
+body_class: 'page-docs-locales'
+---
+
+Uppy speaks multiple languages, English being the default. You can use a locale pack to translate Uppy into your language of choice.
+
+[List of our locale packs](#List-of-locale-packs)
+
+## Using a locale pack from npm
+
+This is the recommded way. Install `@uppy/locales` package from npm, then [choose the locale](#List-of-locale-packs) you’d like to use: `@uppy/locales/lib/LANGUAGE_CODE`.
+
+```bash
+npm i @uppy/core @uppy/locales
+```
+
+```js
+const Uppy = require('@uppy/core')
+const German = require('@uppy/locales/lib/de_DE') // see below for the full list of locales
+const uppy = Uppy({
+  debug: true,
+  locale: German
+})
+```
+
+## Using a locale pack from CDN
+
+Add a `<script>` tag with Uppy bundle and the locale pack you’d like to use. You can copy/paste the link from the CDN column in the [locales table](#List-of-locale-packs). The locale will attach itself to the `Uppy.locales` object.
+
+```html
+<script src="https://transloadit.edgly.net/releases/uppy/v1.0.0/uppy.min.js"></script>
+<script src="https://transloadit.edgly.net/releases/uppy/v1.0.0/locales/de_DE.min.js"></script>
+
+<script>
+var uppy = Uppy.Core({
+  debug: true,
+  locale: Uppy.locales.de_DE
+})
+</script>
+```
+
+## Overriding locale strings for a specific plugin
+
+Many plugins come with their own locale strings, and the packs we provide consist of most of those strings. You can, however, override a locale string for a specific plugin, regardless of whether you are using locale pack or not. See the plugin documentation for the list of locale strings it uses (for example, [here’s Dashboard](http://localhost:4000/docs/dashboard/#locale)).
+
+```js
+const Uppy = require('@uppy/core')
+const DragDrop = require('@uppy/drag-drop')
+const Russian = require('@uppy/locales/lib/ru_RU')
+const uppy = Uppy({
+  debug: true,
+  autoProceed: true,
+  locale: Russian
+})
+uppy.use(DragDrop, {
+  target: '.UppyDragDrop',
+  // We are using the ru_RU locale pack (set above in Uppy options),
+  // but you can also override specific strings like so:
+  locale: {
+    strings: {
+      browse: 'выберите ;-)'
+    }
+  }
+})
+
+```
+
+## List of locale packs
+
+<!-- md list_of_locale_packs.md -->
+
+## Contributing a new language
+
+If you speak a language we don’t yet support, you can contribute! Here’s how you do it:
+
+1. Go to the [uppy/locales](https://github.com/transloadit/uppy/tree/master/packages/%40uppy/locales/src) directory in the Uppy GitHub repo.
+2. Go to `en_US.js` and copy its contents, as English is the most up-to-date locale.
+3. Press “Create new file”, name it according to the [`language_COUNTRY` format](http://www.i18nguy.com/unicode/language-identifiers.html), make sure to use underscore `_` as a divider. Examples: `en_US`, `en_GB`, `ru_RU`, `ar_AE`.
+4. Paste what you’ve copied from `en_US.js` and use it as a starting point to translate strings into your language.
+5. When you are ready, save the file — this should create a PR that we’ll then review 🎉 Thanks!