Initialized flipper-plugin library

Summary: Set up an initial library which can (should) be used by plugins in the future.

Reviewed By: jknoxville

Differential Revision: D22019554

fbshipit-source-id: 502b14b34b2c9c117cea377ab6ebbf150e6faee9

desktop/.eslintrc.js

@@ -14,6 +14,7 @@ const pattern = /^\*\r?\n[\S\s]*Facebook[\S\s]* \* @format\r?\n/;
 
 const builtInModules = [
   'flipper',
+  'flipper-plugin',
   'react',
   'react-dom',
   'electron',