Update formatting.md

You already have prettier support, just making the docs reflect that.

Author: Kevin Newton

docs/formatting.md

@@ -6,13 +6,10 @@ The language server currently supports formatting via the following formatters:
 - [Standard](https://github.com/testdouble/standard)
 - [Rufo](https://github.com/ruby-formatter/rufo)
 - [Rubyfmt](https://github.com/penelopezone/rubyfmt)
+- [Prettier](https://github.com/prettier/plugin-ruby)
 
 ## Configuration
 
 Configuration for formatting is provided by the `ruby.format` key
 
 The global `useBundler` setting is used to determine if the format command should be prefixed with `bundle exec`
-
-## Prettier for Ruby
-
-This extension will not support formatting via the Ruby plugin for [prettier](https://prettier.io/). If you'd like to use this formatter, set `ruby.format` to `false` and install `vscode-prettier` according to [their directions](https://prettier.io/docs/en/editors.html#visual-studio-code).