Finish syntax highlighting

[daveyarwood]

Currently very basic, not all the things are implemented.

TODO:

• [x] voices
• [x] markers
• [ ] cram brackets (just highlight the curly braces)
• [ ] event sequences (just highlight the brackets)
• [ ] Improve highlighting of instrument calls
  • make this a region containing the things to be highlighted?
  • it might be good to only highlight the main "thing"
    • i.e. if there is an alias, just highlight the alias
    • otherwise, highlight each instrument
• [x] Fix Clojure expression highlighting
  • nested expressions don't work yet (https://github.com/daveyarwood/vim-alda/commit/53f05ec2fe48216d364a037dd0bf1aa0426c0719)
  • is it possible to use Clojure syntax highlighting just in that region?

[daveyarwood]

Clojure expression highlighting (mostly) fixed via https://github.com/daveyarwood/vim-alda/commit/8fce7be2622f973e23f8d8934919eb779048ee08

There are some rough edges, like Clojure keywords aren't highlighted, and clojure.core functions like rand-int are only highlighted up to the hyphen, but I think this is good enough for now. It looks way better than it did before.