Add 5.1 instructions (#12760)

UPGRADING.md

@@ -6,6 +6,114 @@ This guide is useful to figure out what you need to do between breaking changes.
 
 As always, [submit issues](https://github.com/FortAwesome/Font-Awesome/issues/new) that you run into with this guide or with these upgrades to us.
 
+## 5.0.x to 5.1.0
+
+### New packages available for browser-only integration
+
+**If you were previously using @fortawesome/fontawesome you need to switch to one of the new packages.**
+
+Our Free and Pro CDN provide access to JS, CSS, sprites, and separate SVG files.
+
+We've now made these files conveniently available through NPM.
+
+* [@fortawesome/fontawesome-free](https://www.npmjs.com/package/@fortawesome/fontawesome-free)
+* @fortawesome/fontawesome-pro (private package, requires Pro subscription)
+
+If you are familiar with the paths and options available with the CDN these
+packages should be familiar.
+
+Information about [Font Awesome Pro subscriptions](https://fontawesome.com/pro)
+can be found in your [Font Awesome awesome
+account](https://fontawesome.com/account/services).
+
+### Renamed packages
+
+The following packages have been renamed as part of 5.1.0 of Font Awesome.
+
+_All packages are in the [@fortawesome NPM scope](https://www.npmjs.com/search?q=scope:fortawesome&page=1&ranking=optimal)_
+
+| Old package(1)            | New package            |
+|---------------------------|------------------------|
+| fontawesome-free-webfonts | fontawesome-free       |
+| fontawesome-pro-webfonts  | fontawesome-pro        |
+
+(1) Old packages have now been deprecated. They are still available but will only receive high priority patch release fixes.
+
+**You'll need to update your package.json file with the renamed packages and new versions.**
+
+### No more default imports
+
+Recently we spent a good deal of time supporting TypeScript to enable us to
+create the Angular Font Awesome component. During that adventure we
+[were](https://basarat.gitbooks.io/typescript/docs/tips/defaultIsBad.html)
+[convinced](https://blog.neufund.org/why-we-have-banned-default-exports-and-you-should-do-the-same-d51fdc2cf2ad)
+that we were going to remove default exports from all of our components,
+libraries, and packages. This is complete with the umbrella release of `5.1.0` of Font Awesome.
+
+What does that mean?
+
+~~Old way:~~
+
+```javascript
+import fontawesome from '@fontawesome/fontawesome'
+import solid from '@fortawesome/fontawesome-free-solid'
+import faTwitter from '@fortawesome/fontawesome-free-brands/faTwitter'
+import FontAwesomeIcon from '@fortawesome/vue-fontawesome'
+
+import fontaweome.library.add(solid, faTwitter)
+```
+
+New way:
+
+```javascript
+import { library } from '@fontawesome/fontawesome-svg-core'
+import { fas } from '@fortawesome/fontawesome-free-solid'
+import { faTwitter } from '@fortawesome/free-brands-svg-icons'
+import { FontAwesomeIcon } from '@fortawesome/vue-fontawesome'
+
+import library.add(fas, faTwitter)
+```
+
+This is also a valid way to import icons that works if your tool does not support tree shaking:
+
+```javascript
+import { faTwitter } from '@fortawesome/free-brands-svg-icons/faTwitter'
+```
+
+### Improved support for tree shaking
+
+Tree shaking is now functional by default and no additional configuration is required to make it work.
+
+The `shakable.es.js` module has been removed and is no longer needed.
+
+If you've previously configured tree shaking by modifying your webpack or rollup you can safely remove these.
+
+**We recommend that you check your bundle size after upgrading an ensure that file sizes are as you would expect.**
+
+```javascript
+module.exports = {
+  // ...
+  resolve: {
+    alias: {
+      '@fortawesome/fontawesome-free-solid$': '@fortawesome/fontawesome-free-solid/shakable.es.js'
+    }
+  }
+}
+```
+
+```javascript
+const alias = require('rollup-plugin-alias')
+
+rollup({
+  // ...
+  plugins: [
+    alias({
+      '@fortawesome/fontawesome-free-solid': 'node_modules/@fortawesome/fontawesome-free-solid/shakable.es.js'
+    })
+  ]
+})
+```
+
 ## 5.0.x to 5.0.6
 
 ### SVG Attribute was changed from data-fa-processed to data-fa-i2svg