Add github links to changelog

Summary:
thefutureisnowoldman

Changelog: Changelog entries now link to their GitHub commits

Reviewed By: passy

Differential Revision: D22999105

fbshipit-source-id: 77e4884a3515245ba9296d8c4f59cdcb3c4b098d

desktop/scripts/generate-changelog.js

@@ -66,7 +66,7 @@ hgLog
       const match = diffline.match(changeLogLineRe);
       if (match) {
         changes++;
-        contents += ` * ${diff} - ${match[2]}\n`;
+        contents += ` * [${diff}](https://github.com/facebook/flipper/search?q=${diff}&type=Commits) - ${match[2]}\n`;
       }
     });
   });