Add LDoc based (source generated) documentation

[Tieske]

This should make it easier to keep the documentation up to date, since it is inline.

It has 3 commits;

• adding a query method to supplement similar other ones
• implementing LDoc based documentation (fixing many bad tags etc. that were already present)
• adding the rendered documentation itself

Creating it as a draft PR first for review, and discussion. Check out the branch and point your browser to ./docs/index.html to see the results.

[Tieske]

@EvandroLG I rebase after the other 2 PR's were merged. If you like the idea, then this is essentially good to go. Marking it as ready for review.