Instead of iterating over lines and tokens (and find comments between
tokens in the comment rules), add a new `Comment` type and set rules
with `type = 'comment'`.
Previously only comments that were indented like the following content
line were allowed, e.g.:
prev: line:
# commented line
current: line
With this change, such new cases are also allowed:
prev: line
# commented line 1
# commented line 2
current: line