install needs electron module installed globally

Let me know if this is not correct.

README.md

@@ -28,10 +28,13 @@ Unpack the latest app from the [releases][0] tab
 Releases available soon, for now build the binary using
 
 ````
+npm install -g electron
 npm install
 npm run package --all
 ````
 
+Run the binary using `electron .`
+
 ## Upgrade from 0.x
 
 Download the latest 0.2.x version, this will give you an option to export any project for 1.x.
@@ -64,4 +67,4 @@ Manage projects
 </h3>
 ![Manage projects](assets/screenshot-4.png)
 
-[0]: https://github.com/redound/graphql-ide/releases
+[0]: https://github.com/redound/graphql-ide/releases