README.md: Proper Markdown formatting

This way the main github page is much nicer formatted. Also, add some
additional information.
Merge pull request #202 from aburgm/markdown-improve

README.md: Proper Markdown formatting
Added machinery for eprint/ADSASS graphics
Merge pull request #203 from ehenneken/ticket_637

Added machinery for eprint/ADSASS graphics
Activated e-print images
Merge pull request #204 from ehenneken/ticket_637

Activated e-print images
added JSON output to export image info
Merge pull request #205 from ehenneken/ticket_637

added JSON output to export image info
doc fixes
added architectural readme
 more readme
more docu
more docs
documentation and test fixes for js code