functional category to come from fg annotation, remove --include-batch-freq

[Lipastomies]

Related issues: #183, #184 List of changes:

• Change functional category information to come from finngen annotation's most_severe column -> it is same column but with only some outcomes. Chosen consequences are

  transcript_ablation
  splice_donor_variant
  stop_gained
  splice_acceptor_variant
  frameshift_variant
  stop_lost
  start_lost
  inframe_insertion
  inframe_deletion
  missense_variant
  protein_altering_variant

• Remove --include-batch-freq option, which included all columns in finngen annotation named IMP, INFO, AMP*
• add columns FG_INFO, n_INFO_gt_0_6 to come from finngen annotation. These are added to the variant report.
• Clean up readme somewhat, separate top report script into its own section there. Remove batch freq mentions there and mark LD report as deprecated.