Adopt community convention for XQuery modules

[joewiz]

Minimally incorporates the following suggestion from eeditiones/tei-publisher-app#194:

File extensions: For file extensions, use the .xq file extension for main modules and .xqm for library modules.

… but ONLY at jinks top-level application package - not for any of the generated application packages.

(Note to self: Look into whether it's possible to create a profile that could apply the convention to legacy apps... and thereby hopefully facilitate adoption of the community convention.)

Update (2025-11-05): As noted below, I've added a commit applying the change across the app, not just the top-level package.

[joewiz]

I have rebased this PR. Already, I think the way the PR clarifies the nature of the main modules (like api.xq) vs. library modules (like config.xqm) is helpful.

I'm wondering whether TP10 would be a good time to apply this change to the rest of the repository - i.e., to all generated apps too. I assume everyone will be touching every piece of code to adapt to TP10 anyway, so this might be the least disruptive time to adjust the project's file extension conventions. To TP-generated app maintainers, this would also signal whether an app is of the 10 era or pre-10 era.

[joewiz]

I added a 2nd commit applying the community convention to all files across the repository. CI tests pass.

IF (that's a big "if") you are interested in this expanded PR, I would happily add a commit to the PR updating the documentation to reflect the new convention and add a section describing the change for users updating.

[joewiz]

I performed a directory diff comparison of a documentation app generated before and after this PR and confirmed (1) that the app generated with the PR works normally and (2) the only changes are to the XQuery module filenames and references thereto.