[DOC]: Use doxygen tagfiles for better cross-project references

[alliepiper]

Is this a duplicate?

• I confirmed there appear to be no duplicate issues for this bug and that I agree to the Code of Conduct

Is this for new documentation, or an update to existing docs?

Update

Describe the incorrect/future/missing documentation

Each CCCL subproject has a separate Doxyfile, so the documentation parsers don't know about the other projects.

Doxygen offers "tagfiles" (https://stackoverflow.com/questions/15274074/what-exactly-is-in-a-doxygen-tagfile) that would allow our subprojects to be aware of each other.

See API-relevant issue here: #8161 (comment)

If this is a correction, please provide a link to the incorrect documentation. If this is a new documentation request, please link to where you have looked.

No response

[bernhardmgruber]

Each CCCL subproject has a separate Doxyfile

Why do we actually need that? Can we just have one?

[alliepiper]

Why do we actually need that? Can we just have one?

With enough tokens, anything is possible