Update installation.md

Author: tannerlinsley

docs/installation.md

@@ -1,15 +1,17 @@
 # Installation
 
-Install React Table as a dependency using `npm` or `yarn`
+Install the React Table v7 Alpha as a dependency using `npm` or `yarn`
 
 ```bash
 # NPM
-$ npm install react-table
+$ npm install react-table@next
 
 # Yarn
-$ yarn add react-table
+$ yarn add react-table@next
 ```
 
+> NOTE: `@next` is only required tempororarily while work on the alpha and beta versions are still shifting.
+
 To import React Table:
 
 ```js