Embedded JS should change the comment prefix to //

[bedge]

Just started using the embedded JS feature. This is fantastic. Thank you for the plugin.
One thing I noticed is the "comment line" function, Cmd-/, prefixes the line with #, not //.
While the # would be a correct YAML comment, it would only be so if it were on column 1, but it's not, it's at the leading edge of the JS code, where, in this context it needs to be a // to be a legally interpreted JS comment.
(At least, that's the case for GitHub actions JS embedded in YAML: https://github.com/actions/github-script)

eg:
What "comment line" does now, with JS embedded in YAML:

For the YAML comment case, this should be:

For the JS case it should be: