add "main" field in package.json - fixes sindresorhus#23

sindresorhus · sindresorhus · commit a16c76cfcb06 · 2016-01-23T13:16:13.000+01:00
diff --git a/package.json b/package.json
@@ -9,6 +9,7 @@
     "email": "sindresorhus@gmail.com",
     "url": "sindresorhus.com"
   },
+  "main": "github-markdown.css",
   "engines": {
     "node": ">=0.10.0"
   },
