Branch pruning day and Readme update festival

[crtahlin]

Periodic housecleaning of repos and code is needed.

As part of this ticket, do the following, in the current repo:

• go through all the branches and prune those not needed anymore; and merge those that were forgotten to be merged -> end result: we have only the branches that we need and are working on
• go through Readme file to see if any updates are needed; the Readme file should contain at least basic instructions on what the repo is about and how to spin up software
  • if there is a lot of effort to update Readme, make a special issue with list of what would need to be updated
  • if small updates are needed, do it immediatelly