Implement eclipse.org new look and feel with Bootstrap 3.4.x

We've decided to implement eclipse.org new look and feel in Bootstrap 3.4.x and Bootstrap 5.X In en effort to keep it simple for our projects to migrate to our new look and feel.

In Q4, the objective is simply to focus on Bootstrap 3.4.x. The top priority are the main sections of our template (MVP: Header, footer, and base styles).

The expectation is that we can update our PHP and Hugo template at the end of the quarter in order to allow us to share a preview with the community on staging in January. In early January, I will publish a blog post introducing our new look and feel to the community and ask them to provide feedback.