LibreJS compatibility

Hi!

The FSF rated GitLab grade "C" as a code hosting platform, as the second best (as in ethically) code hosting platform among the rated platforms.

I cite the FSF:

Things that prevent GitLab from moving up to the next grade, B:

• All JavaScript code served to the client is free, but does not work with LibreJS enabled. (B0)
• Encourages bad licensing practice, including no license; failure to state the license on each source file; and failure to say which GPL versions apply. (B2)

I think the first one is easily fixed, as that "just" requires a header in Javascript files that are served to the user. The second one would be a separate issue imo, as that requires (a lot) more work.

In any case, LibreJS compatibility would by nice in any case for LibreJS users.

I can try to personally tackle this issue, if the GitLab team were to accept patches for this. Let me know if you would accept patches for this.