Please add ndjson

[MalerasMek-Mikael-Lovqvist]

Is there an existing issue for this?

• I have searched the existing issues

What is the missing lexer?

ndjson is newline delimited JSON. I don't know if .ndjson is the most commonly used file extension but I know that the format itself is common when exporting a bunch of serialized objects, or, in my case when storing the output from jq.

I might try to contribute this myself but I'll request it here in case it is a super quick and simple thing for someone with the right experience.

Thank you for a great project!

Links to existing syntax definitions

I don't know if this is relevant but I'll include it in case it is: https://github.com/ndjson/ndjson-spec