Add support for Markdown javadoc

[Juuxel]

Adds support for MD comments using a new CommentStyle enum. All the old methods dealing with comments are assumed to use HTML, and new overloads of all methods have been added to support either CommentStyle.

The Enigma and Tiny v2 formats have a change to accommodate the Markdown javadoc. The Enigma marker for MD comments is MDCOMMENT instead of COMMENT, and the Tiny v2 marker is md instead of c.

# Enigma
CLASS Foo Bar
    MDCOMMENT Hello world

# Tiny
c Foo Bar
    md Hello world

When regenerating the test files, some other changes appeared that are unrelated to this PR. Not sure if they're something to fix later.

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TODO:

• Expand test coverage to cover all javadoc targets (class, field, method, arg, var)