Merge branch 'source-design-merge' into waterfall

Author: Kully

.gitignore

@@ -16,3 +16,7 @@ node_modules
 .sass-cache
 .DS_Store
 .jekyll-metadata
+
+vendor/bundle
+.bundle
+_posts/python/fundamentals/static-image/images

Contributing.md

@@ -5,7 +5,7 @@ Edit or add files in the `_posts` folder in the [source-design-merge](http://git
 1. Clone the repo and then check out the source-design-merge branch:
 
   ```
-  $ git clone git@github.com:plotly/documentation.git
+  $ git clone https://github.com/plotly/documentation.git
   $ git fetch origin
   $ git checkout source-design-merge
   ```