fix: add getting started to README

Author: ryanolsonx

README.md

@@ -7,3 +7,14 @@ A replacement of the definitions functionality from the original Atom-IDE / Nucl
 ## Features
 
 * Go to definition (using keymap or context menu).
+
+## Getting Started
+
+1. Install `atom-ide-definitions` in Atom.
+
+2. Install an IDE language package that you would like to use:
+  * TypeScript & JavaScript [ide-typescript](https://atom.io/packages/ide-typescript)
+  * Python [ide-python](https://atom.io/packages/ide-python)
+  * Rust [ide-rust](hhttps://atom.io/packages/ide-rust)
+
+  You can also search for [packages](https://atom.io/packages/search?q=IDE) in Atom.