* Fix conf files to reflect module renaming
Python module was renamed budget → ihatemoney (see #243 and 6923367).
Now, "budget" relates to nothing.
* Harmonize `APPLICATION_ROOT` doc with other settings
* Fix link markup
* Switch documentation to recomend pip over git
- Update installation instruction
- Clearly separate dev setup from installation
- Some rewordings/section-ization by the way
* Add a hint on how to find the static path
This is a downside on the pip choice over git for installation.
We will have to ease that a bit. By doc or by code, before next release.
* Make the nginx deployment doc more accurate
* Add a big fat warning about SECRET_KEY in doc
