Remove docs CI stage, moved to submodule
Summary
Removes the now dormant CI stage "docs", which generates a visualisation of the catalogue schema using Schemacrawler.
Requires manual tests in pre-production
No
References
Solves part of #298
Removes the now dormant CI stage "docs", which generates a visualisation of the catalogue schema using Schemacrawler.
No
Solves part of #298