Add analysis strategies to docs

[julesjacobsen]

There are probably too many confusing example input files in the cli examples directory which leads to people rolling their own sub-optimal analysis steps.

Getting the best from Exomiser should be described in a new section of the documentation. This should include:

• How to choose the most informative HPO terms
• Strategies for analysis e.g. exomiser first followed by genomiser
• Examine the top 5 candidates
• Use the most recent version and data release
• How to analyse a trio or quad.
• Maybe some worked examples?

[pnrobinson]

This article can be cited for choosing HPO terms -- https://pubmed.ncbi.nlm.nih.gov/31479590/