Replace the "Eclipse Foundation Events" section by a "Purpose" section

Created by: Mogztter

I think we should replace (or at least move it lower on the page) the "Eclipse Foundation Events" as it can be a bit misleading.

Here's the current content:

As you can see "Eclipse Foundation Events" section takes a lot of space and even draw the attention away from the hero section.

I think we should instead use this section to describe the purpose/mission of the Working Group. Here's an example:

https://science.eclipse.org/