Add more resources for Austria

The resources were gathered by Meral Akin-Hecke and I'm helping her to
put them online. I've converted them to HTML and structured them a bit,
but I don't speak German so I suggest we send the link to the merged
resource page to Meral and ask if she wants us to make any changes.
Merge pull request #102 from mitio/resources-austria

Add more coding resources for Austria
Add coding resources in Bulgarian for Bulgaria