Modernize ActiveMQ Website

[sergio-d-lemos]

Create a new website with a more modern look and feel and also aligned with other Apache projects. At least initially, the content should remain the same. This is also an apportunity for fixing broken links thare still linger here and there.

I think we should keep it simple and continue some sort of static website generator.

Open questions:

1. Should we use https://infra.apache.org/asf-pelican.html or use some other platform (Hugo, Jekyll, etc...) and some JS/CSS framework (Tailwind, Bootstrap, etc...).

[mattrpav]

@sergio-d-lemos dropping a couple mock-up screenshots, or links to a live demo site in this issue would be super helpful =)

edit: Also-- this issue should move to the activemq-website GH project.