Dev docs merge
The aim of this MR is to allow https://dev.thorchain.org/ sync with this repo within the docs folder.
The MR combines the current https://dev.thorchain.org/ content into the thornode/docs
folder ready to enable a Gitlab and Gitbook sync, so all documentation can be served in https://dev.thorchain.org/.
The Summary.md allows control of the table of contents so a deeper hierarchy without changing the physical file structure - as we don't want to move ADR file locations.