Add git repository field

So we can go to the GitHub repo from NPM

Author: satya164

package.json

@@ -5,6 +5,7 @@
   "main": "lib/index.js",
   "module": "es/index.js",
   "license": "MIT",
+  "repository": "[email protected]:FormidableLabs/prism-react-renderer.git",
   "files": [
     "es",
     "lib",