Update docs website

[ScottyPoi]

This has not been updated for 2 years.

• Links need updating
• New packages need links
• Update examples and use-case instructions
• Include up-to-date docs and install guides
• Could use a snazzier UI

[holgerd77]

Also made another comment on this "somewhere else" [TM] 😋 (with tldr; throw away at some point eventually respectively redo very differently), just a note that it nevertheless very much makes sense to do this as a 2-step-process and in a first round just do a all-what-is-necessary update so that this somewhat aligns back with the recent state without too much effort.