Tweaks to <h2> header text since it was getting truncated by the "collapsible" functionality.
Update to preview template

- Added in article.js and a CSS override so collapsible elements can be properly previewed on mobile.
- Deleted anything that might cause JS errors
- Removed elements from the sidebar nav so it's easier on the eyes
Merge pull request #105 from pearlchen/remote-debugging

Tweaks to Remote Debugging <h2> header text
Merge pull request #106 from pearlchen/preview-template-updates

Update to preview template