Demos: Remove prettify load from demo table

Not used after the switch to the demo generation since the frontmatter
doesn’t allow html tags
Merge pull request #4184 from nschonni/v4-demo-remote-table-prettify

Demos: Remove prettify load from demo table
Forms: Added Bootstrap CSS to the submit and reset buttons (fixes #4135)
Merge pull request #4188 from pjackson28/addbootstrapformbuttons

Forms: Added Bootstrap CSS to the submit and reset buttons (fixes #4135)