• This comment contains a description of changes (with reason)

This is a PR for a new module, haplocheck, specifically for its contamination output.

• There is example tool output for tools in the https://github.com/MultiQC/test-data repository or attached to this PR
• Code is tested and works locally (including with --strict flag)
• Everything that can be represented with a plot instead of a table is a plot
• Report sections have a description and help text (with self.add_section)
• There aren't any huge tables with > 6 columns (explain reasoning if so)
• Each table column has a different colour scale to its neighbour, which relates to the data (e.g. if high numbers are bad, they're red)
• Module does not do any significant computational work