Activate on gjs files

[NullVoxPopuli]

It doesn't seem like Glint is active or provides help on (g)js files atm. This would be good to add.

(or we've ported so few features over from tsc, that I can't even tell its on, see: #626 )

[dfreeman]

Have you followed the docs? It certainly works.

[NullVoxPopuli]

Yes, maybe i have a different issue that just manifested goofy, i'll investigate in a bit