Update outdated pvpmc.sandia.gov links in user guide

[reepoi]

• Closes Outdated pvpmc.sandia.gov links in user guide. #1788
• I am familiar with the contributing guidelines
• [ ] Tests added
• [ ] Updates entries in docs/sphinx/source/reference for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• [ ] New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

Fixes the two links mentioned in the issue. I am unsure what link to use for the PV_LIB Matlab help webpage.

[cwhanse]

I would point the PVLib for Matlab link to https://github.com/sandialabs/MATLAB_PV_LIB

[kandersolar]

Thanks @reepoi!

As an aside, I recall there being some way to automatically detect broken links during the sphinx build. Maybe something to consider for the future.

[echedey-ls]

automatically detect broken links during the sphinx build

Mind if I open a PR for that? It's just a line of code.

[kandersolar]

@echedey-ls sure! My first thought is that it might significantly slow down the docs build, depending on what URLs it checks (e.g. every docstring DOI might take a long time...). Depending on that, we could add it to the CI, or just run it manually every so often. Probably broken links should be reported as warnings, not failures.

[echedey-ls]

@kandersolar I've been looking a bit more into it.

For internal references there is the config value nitpicky = True, that would be useful but does not solve the problem. I think it is good enough to add: I'll open a PR at least for that.

On the other hand, for external links linkchecker builder has to be run.
I'm looking for a way to integrate it. From this comment it seems a bad idea to trigger that on every PR. In fact, all that conversation gives a good insight on how many things can go wrong with it.

I don't know how could I even take all the linkchecker output and create a test triggering that and determine if it passes or fails. There are many other occurrences out there to do link-checking, but I'm unable to find something that may work for PVLIB without problems.

Anyway, IMO the most promising approach is the one that is currently done at Matplotlib. See this instructions on the release procedure. And sorry for not bringing a better solution.

If an action could be made out of that, an action running weekly or so would be nice, like this one.