Feature/more documentation

I've added lessons learned from @helmo and move some text around

The follow should become separate issues but we ran into these

- [ ] How to work with Firefox
- [ ] How to work with Safari
- [ ] How to install on Ubuntu 12.04
- [ ] Simple patch workflow

- The Chrome workflow is easy as already described.
- While installing on debian we learned the supported packages were not good enough. After installing the node binary in HOME all went ok. Should we document this or add links?
- For writing a single patch we have a steep learning curve. Can we do better?