Updated Contributing GIF in README (freeCodeCamp#264)

* update contribution gif url

* Add updated contribution gif

README.md

@@ -30,7 +30,7 @@ You can create a PR with your draft article (or edits on an existing article) in
 
 1) The easiest method is to use the GitHub interface. Watch the video demonstration or follow the steps below it:
 
-![Gif showing the GitHub interface steps](https://files.gitter.im/FreeCodeCamp/building-guides/WPK4/guide-article-contribution.gif)
+![Gif showing the GitHub interface steps](https://i.imgur.com/0cmxJwN.gif)
 
 - Go into the "pages" folder (located in `guides/src`) and find the article stub you'd like to write or edit. All stubs will be in an index.md file
 - Click the "Edit this file" pencil icon and make your changes to the file in GitHub-flavored Markdown