Add link to docs

Author: andyw8

README.md

@@ -32,6 +32,10 @@ Nested models (e.g. `Admin::User`) are not yet supported.
 Note: When using the Test Explorer view, if your code contains a statement to pause execution (e.g. `debugger`) it will
 cause the test runner to hang.
 
+### Documentation
+
+See the [documentation](https://shopify.github.io/ruby-lsp-rails) for more in-depth details about the supported features.
+
 ## How It Works
 
 This gem consists of two components that enable enhanced Rails functionality in the editor: