Move standard docs to root (#1454)

CONTRIBUTING.md

@@ -72,7 +72,7 @@ Here are a few things you can do that will increase the likelihood of your pull
 - Write a [good commit message](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html).
 
 ## Releasing a new Primer CSS version
-See [RELEASING.md](./RELEASING.md) for our release process.
+See [RELEASING.md](RELEASING.md) for our release process.
 
 ## Resources
 

README.md

@@ -51,10 +51,10 @@ You can import individual Primer modules directly from the `@primer/css` package
 ```
 
 ## Development
-See [DEVELOP.md](./.github/DEVELOP.md) for development docs.
+See [DEVELOP.md](DEVELOP.md) for development docs.
 
 ## Releasing (for GitHub staff)
-You can find docs about our release process in [RELEASING.md](./.github/RELEASING.md).
+You can find docs about our release process in [RELEASING.md](RELEASING.md).
 
 ## License