Add linkcheck to sphinx build

[tkoyama010]

Discussed in https://github.com/pyvista/pyvista/discussions/1539

^{Originally posted by tkoyama010 July 23, 2021} There is a option to check the integrity of all external links in sphinx-build option. This will be a good first issue in Scipy2022.

[laysauchoa]

Hi, I'd love to contribute to the pyvista project. Would be possible to assign this issue to me? Thanks!

[tkoyama010]

@laysauchoa Thanks for contributing! We welcome your contribution.

[laysauchoa]

Before adding this workflow, let's clarify some important points:

I can add one workflow to run for all the files in every push Advantages: catch any link that fails in every push Disadvantages: it may make things slow if you have there are too many links

OR

I can add two workflows:

• one to run in every push only in the changed files
• one to run weekly in the whole file

Advantages: runs faster and avoid false positive. Some pages are only temporarily unreachable. Disadvantages: maybe something fails in between and you will only catch in a week basis

ping @tkoyama010

[tkoyama010]

Nice analysis, I think it would be clearer if you measured the time with PullRequest.

[laysauchoa]

linkcheck will take 35 min or a bit more. wdyt? I'd say that running periodically would make more sense to not have to wait for this long. However, a link could break in between.

[akaszynski]

Might make sense to run this as a weekly cron job.