A few changes:
* 0-arity type specs like the following previously would not have the
expected 'variable.parameter' highlighting for the return type:
-spec foo() -> Value when Value :: term().
* Highlight module, type and function docs as documentation comments
and inject markdown into them.
* Replace `#match?` predicates with `#any-of?` where possible.
* Remove custom auto-pairs. Now that Erlang uses markdown for
documentation, the asciidoc-style backtick-singlequote pair is no
longer useful.
This highlights edoc within Erlang comments. The trick was to have
the Erlang grammar consume newlines and then give them to EDoc in the
injection to use so that line-wise elements could be parsed accurately.
