Should `layer` be syntax highlighted?

[TylerLeonhardt]

@import url('bootstrap/scss/bootstrap.scss') layer(bootstrap);

Originally posted by @TylerLeonhardt in #180631

[aeschli]

I the css grammar, the layer in layer(bootstrap) is not correctly parsed/highlighted

[andreamah]

duplicate of #17

[romainmenke]

@andreamah This is not a duplicate of #17

#17 is for @layer statements and rules.

@layer {
  /* some css */
}

This issue is for layer functions and keywords in @import statements.

@import "foo.css" layer(base);