[r] Publish tiledbsoma on CRAN

[mlin]

Follow-up from #1427

All agree we should publish tiledbsoma on CRAN to make installation as simple as possible for users and dependent packages. There were some differing opinions on when we should begin publishing on CRAN (how mature we should be) given that the CRAN maintainers may frown on updating packages there too frequently. In the meantime we're publishing through r-universe (configured to track GitHub Releases).

This ticket is to decide when it's the appropriate time for CRAN, write down the "procedure" in doing so, and update the readme to point users there instead of r-universe.

[mojaveazure]

One thing to note about CRAN: packages are required to be cross-platform

Package authors should make all reasonable efforts to provide cross-platform portable code

Exceptions can be made (à la {unix}), but I believe CRAN's preference is for all packages to work on Windows, macOS, and a few flavors of Linux (Debian and Fedora)

@eddelbuettel please correct me if I'm wrong

[eddelbuettel]

Like many things that is a preference and a desire but not a hard constraint. We do build on two common platforms, that should be good enough. DESCRIPTION has a field OS_type with value 'unix' for a few packages. So that is not a blocker. None of what you said is wrong but in aggregate it simply is not a constraint. There are (were?) even Windows-only packages. "It all depends" and can be explained.

[johnkerl]

@eddelbuettel should this now be closed in favor of #1582?

[eddelbuettel]

@johnkerl I will leave the juggling of overlapping / partily redundant issue tickets in your capable hands. Works for me either way, you may want to consult with @mlin too before closing / merging / extending.

[mlin]

@johnkerl @eddelbuettel No objection to merging. Comparing the tickets, it looks to me like the only extra items noted in this one are (1) update our written release procedures to reflect publishing to CRAN and (2) update the user-facing readme/docs to refer to CRAN instead of r-universe. Perhaps obvious but certainly part of the scope.