Add documentation on GitHub repositories

[planetf1]

It would be useful to capture key information about the GitHub repositories we use for Egeria.
This is primarily for developers.
The information could contain

• Name of repo
• Link to repo
• Owner(s)/Admin [github ids]
• Description/purpose - what this repo is all about
• Dependencies on other egeria repos (compile, test, runtime)
• Other repos dependent on this (could omit as duplicate of above and more to maintain)
• What is provided by repo - build artifacts/attachment, raw jar/lib from build, maven packages (where), docker images, charts etc [need to dig into this categorization further], github releases. include links
• Where issues should be raised (link) - could be main egeria, or actual repo (more likely)
• Languages / frameworks in use
• ci/cd methodology/schedule
• release strategy/policy
• security stance/scans

An alternative option is to keep the link in the docs light, with only a repo name/link, and then point to a well defined .md file within each repository. This should be of a mandated format, but is then owned by the linked project. we loose searchability, and it is dependent on each repo making the change. It also may make it tricker to identify inconsistencies

We could model this in egeria.....

[planetf1]

I opened #646 to improve the simple text table listing repos. This covers the first few items above & could be simply extended (ie existing metadata on the repo). Other content could be built from files in a standard format if required