[WIP] Revisiting structure part 1

| Q   | A
| --- | ---
| Doc fix? | yes
| New docs? | no
| Applies to | all
| Fixed tickets | partly #523

During this Community Hack Day, I'll try to work on the revisited doc structure.
Thisnote is about the odm config ism't it? Before, it was placed at the top, I've moved it to just before the odm option. That's more logical to me and it means it's also visible if someone used a headline link to odm directly