Add Variant-Reporting homopolymer expert/filter

This is a description test
max_length and info_field don't need to list the default in the doc.  The help text already does this:

```
  info-field   Text
    Info field id for homopolymer, command default is HOMP_FILTER 
    Default value 'HOMP_FILTER' if not specified
  max-length   Integer
    maximum indel length to annotate as in homopolymer, command default is 2 
    Default value '2' if not specified
```