- use cogeno itself to generate documentation content from templates
  - generates the binding docs for edts and a general index of all
    generated docs
- streamline menu structure to better fit to ReadTheDocs (and other)
  - the welcome page now becomes the documentation index
  - index is mainly to show the side bar in ReadTheDocs
  - show all modules in the module page with the artificial
    split in non standard and standard modules
- streamline module doc content
  - give all modules a similar heading structure
- add a guideline for config/ kconfig
- improve the devicetree guideline for edts
- document all bindings for edts

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>