Fix missing highlighting for unquoted strings

[Alhadis]

This has been missing in seti-syntax for a long time, and it's really made it harder to make syntax highlighting for config files look appealing to Seti users... 😞

Here's a before-and-after:

"Unquoted" strings are basically any line (or block) of text that's interpreted as one long string without needing quotation marks. It's drawn from TextMate's conventions for scope-names in language grammars.

[Alhadis]

@jesseweed Hey buddy, any chance of getting these improvements upstream? :grinning:

Happy new year, BTW. :D

[Alhadis]

... still silence. :cry:

/cc @jessetumbleweed

[jesseweed]

Hey sorry, for the delay! Don't know how I didn't see this until now!

Will try and cut a new release shortly

[Alhadis]

Thanks! :tada: