Document the different databases and entries therein to use for seqvar assessment

[holtgrewe]

Is your feature request related to a problem? Please describe.
We need to implement automated assessment of ACMG criteria (#123,). For this, we need to document the different public datasets that we can use to automatically annotate variants.

Describe the solution you'd like
Collect the different steps in the corresponding Sphinx manual chapter.

Describe alternatives you've considered
N/A

Additional context

• Properly implement computer-aided ACMG assessment for sequence variants. #123
• Document the different rule sets and criteria to incorporate for automated seqvar assessment #188