It would be neat if bat would syntax highlight *.jsonld.

JSON-LD is really just JSON, and e.g. bat --map-syntax='*.jsonld:JSON' test/picasso.jsonld already works great.

JSON LD's Media Type is application/ld+json (and IANA extension *.jsonld).

I guess technically this isn't even a "real" (full-blown) new syntax-request...