README.md: Modernize readme

[JAB1305]

Modernize readme
Closes #475
Superseeds / inspired by #490

Open (for discussion):

• Keep RDF support feature? Is this relevant? (last activity apparently 2y ago)
• Move Eclipse Contributor section to Contributing.md? (no mention there, at least duplicate?)
• Badges for python min / python max point to not yet merged branch (Restructure versions to a single point of truth #610). Should point to main, note that dev readme would then always be outdated on version bump until merged. Acceptable?

[s-heppner]

Thank you for the draft! Let me answer your questions:

Keep RDF support feature? Is this relevant? (last activity apparently 2y ago)

Yes, let's keep it and keep reference to it. If more people know the problems (#422) with it, the more IDTA might change something with their RDF schema.

Move Eclipse Contributor section to Contributing.md?

Makes sense to me. Somewhere we do mention in the CONTRIBUTING.md that you need an Eclipse Account and sign the ECA already.

Should point to main, note that dev readme would then always be outdated on version bump until merged. Acceptable?

Can we not have the badge refer to the current branch's central config file? I don't think a badge on develop with outdated version is good, if someone actively needs a new feature they'd be massively confused.

[JAB1305]

Can we not have the badge refer to the current branch's central config file? I don't think a badge on develop with outdated version is good, if someone actively needs a new feature they'd be massively confused.

Unfortunately I was not able to find a way that allows for branch aware extraction of the version. The current version for the badge references a hardcoded raw.githubusercontent... URL that can in the future be either pointed to main or develop but have no way to just use "current". Also this method can only extract one value, so something like 3.10 - 3.12 in single badge would not be possible.

I think the two best options are either something like this:

(Imagine different version here)

Or to introduce a CI step that surfaces the versions, but that seems a bit overkill.