[Documentation] No documentation contributing guide

[Rubix982]

Is your feature request related to a problem? Please describe.
There are no instructions on how to contribute documentation to the project in the CONTRIBUTING.md

Describe the solution you'd like
Instructions to be added.

Describe alternatives you've considered
An inspiration can be the documentation guide from ceph. See here, https://github.com/ceph/ceph/blob/master/doc/start/documenting-ceph.rst.

Additional context
Documentation needs to be build and published.

[Rubix982]

We do not have a need further for this anymore as the documentation is being generated from the source code itself, and the setup instructions have already been automated in Makefile.