chore: Prepare for v0.7.1. (#93)

chore: Prepare for v0.7.0. (#90)

chore: Prepare for v0.6.1. (#82)

chore: Prepare for v0.6.0 (#64)

chore: Prepare for v0.5.1. (#46)

chore: Prepare for v0.5.0 (#43)

Prepare for v0.4.0. (#26)

Prepare for v0.3.1. (#23)

Prepare for v0.3.0. (#20)

Only recognize well-known comment markers (#11)

Restricting what comment markers keep-sorted accepts leads to less
surprising behavior, such as // go/keep-sorted treating the comment
marker as "// go/" when using the default id of just "keep-sorted".