(yaml) Tags should allow non-word characters

[pplantinga]

Describe the issue
YAML tags can include some non-word characters (e.g. period, dollar sign) but current highlighting only matches letters and underscores

Which language seems to have the issue?
YAML

Sample Code to Reproduce
https://jsfiddle.net/7ukmfhsv/

Expected behavior

[joshgoebel]

Confirmed. Should be a simple fix. PR welcome.

[joshgoebel]

@pplantinga Any chance you'd be interested in #2475? It's gotta be much simpler than this. :-)