Revise Docs overview page

[dmuelle]

Opening this issue to start discussion and track work for improving the docs overview page. Companion issue in OL docs repo is OpenLiberty/docs#5925.

@jgawor comment from that issue:

The docs page (https://openliberty.io/docs/latest/overview.html) has a lot of good content. However, a lot of that TOC is off-screen when initially viewing the page and user needs to scroll to see all the important topics. I think the "Welcome to Docs" page can be improved to show the key (or popular) topics right on that page - e.g. assembled in a set of tables. Example: https://learn.microsoft.com/en-us/azure/developer/java/ee/

We need to figure out a design to display featured/commonly used topics: Possibly topic cards like on the guides overview, but each card provides a list of topics around a given functional area, similar to the azure example. The Quarkus overview allows you to filter the list of callouts based on topic area.
Also TBD is a prioritization scheme to decide which topics to surface. Simply repeating the entire TOC doesn't seem like a worthwhile solution, unless we enable some kind of filtering.

[dmuelle]

#3151 issue to add whats new content to overview automatically

[steven1046]

What if we use data to determine the most common docs everyone goes to and then highlight those in addition to maybe showing cards regarding features, config, javadocs, apis/spis, commands they can run on their servers, etc. to highlight everything they can find in the docs.

[dmuelle]

Great idea- it has been a while since I've seen our GA results about page visits. We might also consider consulting with PMs/ dev leads to identify topics that we want to emphasize from a market perspective (eg instantOn, dev tools), though that would require ongoing maintenance/engagement to keep current.