Add documentation for (default) monitoring
Follow-up of !1636 (merged)
Cherry-picked !1729 (commits) and followed up from !1727 (closed).
The MR includes a few minor fixes of the docs pipeline. Fixes #461 (closed) with !1729 (commits)
Moves documentation for running Hlt1 and Hlt2 consecutively from recoconf to tutorials.
Edited by Marian Stahl