Update README.md

ADD PRODUCTION DESCRIPTION HERE!!!

Instructions

When creating your merge request:

• Add a label for your WG
• Mark as "WIP:" until you're happy with the CI results

When ready:

• Remove the "WIP:" from the title:
• Assign the merge request to you working group's DPA/RTA liaison

To find your working group's DPA/RTA liaison, see this page:

https://twiki.cern.ch/twiki/bin/viewauth/LHCbPhysics/LHCbWGLiaisons