Update how-to-install-and-update.md

Author: Sarah Guthals

docs/using/how-to-install-and-update.md

@@ -3,6 +3,8 @@
 [Installing from the Unity Asset Store](#installing-from-the-asset-store)  
 [Updating a Previously Installed Version](#updating-the-github-for-unity-package)
 
+_Note: If your project is already in a remote repository, see our [Getting Started](https://github.com/github-for-unity/Unity/blob/master/docs/using/getting-started.md) docs before continuing_
+
 
 # Installing from a Package File
 You can download the latest release from the repository at [https://github.com/github-for-unity/Unity/releases](https://github.com/github-for-unity/Unity/releases) or from the website at [https://unity.github.com/](https://unity.github.com/).