The '#' character may either be interpreted as a map when used
like so:

    %% Example 1
    #{a => b}

Or as an operator which updates an existing map when the left-hand
side is an expression:

    %% Example 2
    MyMap#{a => b}

This commit changes the highlight to `punctuation.bracket` when used
as a character in a literal map (example 1) and keeps the `operator`
highlight when used for updating (example 2).

* add punctuation highlights for commas as in function parameters
* remove stray `variable.parameter` highlight
    * I couldn't find any regressions from this and it fixes an
      edge case I ran into (but sadly did not record 😓)
* highlight `fn` as `keyword.function`
    * the theme docs have `fn` as an example so it seems fitting

Punctuation highlights would show up outside of where they
were valid, for example using parentheses in some text. This
change prevents that by gating the captures to being under
the named nodes in which they are valid.

* `/>` as in self-closing tags like `<hr/>`
* `=` as in the separator between attribute name and value `<a href="bar">`

`module` is undocumented and does not exist in other themes. The
equivalent existing scope based on usage (Elixir for example) is
`namespace`.

This includes a fix for the new HTML highlights introduced a few
parent commits back:

    ["\"" (attribute_name)] @string

Would get tripped up and the entire line would be highlighted as
a string. Now `\"` is a valid escape.

I'm switching to my fork as the primary repo as the upstream hasn't
been touched in over a year (mostly because stability afaict) but
it has no watchers currently so I'm not hopeful that my PR will
be merged.

* branch message with current branch and diverged branch has been
  added to the parser
* scissors used in verbose commits are marked as a punctuation
  delimiter
    * we could use comment instead since they're visually the
      same but IMO this works better

You might use a macro like `?MODULE` to name a record:

    -record(?MODULE, {a, b, c}).

With this fix, the record fields correctly get `variable.other.member`
highlights.