Merge pull request #11 from jagrem/master

Add more highlighting support and stylesheet.
Remove custom obsidian styles from the language
Prepare 0.3.0 release
Merge remote-tracking branch 'jagrem/master'
Prepare 0.4.0 release
Merge pull request #16 from jagrem/master

Add automatic variable highlighting to grammar.

Closes #12.
Refactor double-quoted string tests.

Remove the word highlight from test descriptions. Refactor common scope tests into a single test where applicable. Use the word tokenize in preference to tag. Add more detailed descriptions of how elements should be tokenized.
Remove Python magic function sections from grammar.
Remove Python magic variables section from grammar.
Remove Python style docstrings from grammar.
Remove references to built-ins from grammar.