Add a short description for each teacher

[acadet]

It would describe his/her background, the techs s/he likes working with etc.

It would be nice if we can make it visible on the lesson page.

[gkop]

This is a great idea! It's actually a flat haml file committed to source control. I would love to see someone get this started. You can put in something embarrassing for me too and I will jump in and clean mine up.