Now that we use Ruby 2.6 we can fix these last two files.

- Only try to call `.match?` on strings that aren't nil.

Use active voice when applicable, better verbs & adjectives, preposition usage, proper tense, etc.

When reading the comment header of a shell command, omit options that
are in Homebrew::CLI::Parser.global_options, since they are documented
separately for all commands.

Add a regex to handle two comma-separated options on the same line in
command help strings.

This is a clearer branding for us to use.

Also, as part of testing this, make some fixes to Jekyll in the docs folder.

Fixes #5835

Today the Homebrew maintainers elected a new PLC, TSC and project lead.
Documentation is to follow detailing exactly the responsibilities for
each of these roles but adjust these to reflect the current state until
that point.

This provides a more consistent version for `rubocop` than relying on
`Homebrew.install_gem_setup_path!` (and we really want `brew style` to
provide consistent output).

These aren't needed when converting Parser-based help text to man page or Markdown formats.
Includes regenerated docs.

Specifically, `brew ruby -e "<ruby code>"`.

`brew ruby` now accepts only `-e`, verbose, and debug arguments.

- dev-cmd/man: sort the `cmd_path`s (for APFS)
- update manpages based on latest content

Replace <var> tags with markup for italicized monospaced text in Markdown.
This requires the source to not combine bracketed and backticked text.

Work around ronn's inability to nest indents within list items by modifying its output to add a line break and indent after lines ending with a colon that aren't a list item's first line. This allows `brew.1.md.erb` to join the commands' help text without extra line breaks, which avoids the issue where kramdown was turning any command specs containing pipe characters into tables in the HTML output.