More Docsy Updates - Githubissues

This PR includes a lot more changes related to the recent Docsy migration and upcoming site merge.

In particular, this PR contains the following changes:

Updates some CSS styles:
- replaces all of the custom color classes with utility classes from Bootstrap
- scopes problematic heading and padding/margin styles to non-doc pages
- reorganizes existing styles
- though I haven't renamed the existing classes to match the BEM convention. that can come later.
moves all HTML files to layouts/ directory. the content/ directory will be used strictly for content and page resources and metadata
moves all partners logos to a new headless bundle in the content/_partners directory
- also created an archetype for this content
fixes some draft templates that I accidentally broke in my previous PR
disables the slanted footer on the docs pages
moves images used by the layouts/ HTML files to assets/images
marks the user-guide folder contents as draft since they're not ready to be published yet
moves shortcodes to partials so they can be used by the layouts HTML files
uses Hugo image processes to properly resize images instead of using CSS classes
- this has decreased the amount of data sent over the wire pretty significantly. for example, the home page now only transfers 559kB to the client instead of 3.3MB

rapidsai / rapids.ai