[Request] Allow highlighting SQL keywords

[alex-statsig]

I'm using nunjucks to create templated SQL queries. Historically I've named these files .njk.sql, and just used the SQL syntax highlighting. It's really nice to get the nunjucks highlighting for things inside braces though, so I tried out this extension. This makes the nunjucks much easier to read, but the SQL much harder.

I was wondering if there could be some way to specify the fallback language for things not inside braces. I know that it will be hard/impossible to actually fully parse that, since a nunjucks template may conditionally insert some keywords into it, but at least highlighting keywords / string literals where possible would be great (essentially highlight it as if everything nunjucks-related resolved to an empty block).

Right now I have to choose between these two:

SQL	NJK