Don't line wrap paragraphs

The GCN Circulars style guide no longer recommends wrapping long paragraphs. See https://gcn.nasa.gov/docs/circulars/styleguide#message-content.

changed the description

added to epic &5

added O4 label

changed milestone to %O4

changed milestone to %O4a mid-run release

changed epic to &8

I think the line wraps can still be useful for printing out on one's own computer so should be an optional argument where we can turn off the rewrap filter in production. This will also require remove line breaks where possible in the text but there will be instances they should remain (e.g. line breaks in tables).

changed milestone to %O4

removed milestone %O4

changed milestone to %O4a mid-run release

mentioned in merge request !158 (merged)

closed with commit 3884a61d

closed with merge request !158 (merged)