Add color to klippies

Bootstrap and jQuery dependencies are removed.
Glue code is written in Vanilla JS.
Tooltips are rendered using Primer Tooltips.

Auto size klippies (use img from Octicons instead of Glyphicons)

• Change the position of the klippy button (upper left corner instead of upper right corner)
• Add a size argument to klippy()

This is an initial release for testing klippy by users on different HTML R Markdown templates.
Suggestions are welcome !