Adding support for Erlang

[zambal]

Hi, I managed to add Erlang as supported language. I was wondering if there's interest in merging these changes before opening three pull requests (in flow, flow-syntax and tree-sitter) and if the answer is yes, I assume flow and flow-syntax pull requests need to be opened on codeberg.org instead of github.com, right?

[neurocyte]

Yes! Adding erlang support is very welcome!

You can open PRs here or on codeberg. I'm not picky.