`mkEnableOption` wraps its argument in a complete sentence with a
terminating full stop; an additional newline will add an incorrect
space before the end of the sentence in the rendered documentation,
and any additional verbiage that doesn't fit into the form "Whether to
enable [...]." is also incorrect. In the latter case, the description
can be overridden manually.
These all use DocBook markup too complex for `nix-doc-munge` to handle,
have syntax that clashes with Markdown, or already contain Markdown
syntax that currently isn't rendering correctly.
Converting DocBook list syntax makes me think that maybe Markdown
isn't so bad after all.
