refs #147: base docs framework polishing

[stickgrinder]

This PR brings a lot of polishing and introduces a solid and clean deployment procedure. In a nutshell:

• All the docs-related files (docker files, compose yaml, mkdocs conf, scripts, makefile) have been moved into the docs directory.
• We now have cleaner docs/src and docs/dist subdirs for source and build+deploy automation. The dist directory should always stay empty, as it's managed by the makefile.
• DockBlock extraction from code and deployment to gh-pages is working cleanly and has been documented.
• No configuration required. The whole thing is 100% portable as long as you have Docker and make it available.
• Overall polishing and renaming of most make targets.

[mapedorr]

Everything looks good. All seems like dark magic to me.