* move FAQ.md to https://github.com/mimblewimble/docs/wiki/FAQ and unduplicate (Troubleshooting segment already present on its own wiki page)
* Update doc/style and move it into CONTRIBUTING.
* group up docs overview for more clarity
* link to previously unlinked content in the docs overview
* update + cleanup doc/build
* Update links to reflect troubleshooting is now only in the wiki
* More link fixes and spelling
* Remove doc/usage.md that I've faile to keep updated, and use a wiki page instead
* Last forgotten CONTRIBUTING.md fix
* add doc/table_of_contents, initial attempt, based on https://lists.launchpad.net/mimblewimble/msg00024.html
And explain and link to build.md about creating folders server and wallet manually.
* add Files in this folder (doc)
* rename headlines
* docs: extract code and directory structure to code_structure.md