Qiskit
[epic] Check links for API docs
At least the internal links to start. @axelhzf has a good point that it would be ideal to avoid 404s in our site, even if they are for outdated docs not many are looking at.
[Outdated] adding the mechanism to check
We should add an argument like --historical-apis to the link checker and only use it in CI, probably the cron job.
We want to be careful to not slow down performance too badly when implementing this. Per https://github.com/Qiskit/documentation/pull/496, the key is to avoid loading more files into memory than necessary.
We should process each historical API version atomically. For example, 0.44 docs should not be linking out to anything else but other 0.44 files and external links. So, we should entirely process 0.44 docs at once, then drop it from memory. Then go on to 0.43, etc.
How to fix broken links
Some of the broken links have been due to bugs in our script, like https://github.com/Qiskit/documentation/issues/542 and https://github.com/Qiskit/documentation/issues/732. Legit issues will need to be fixed via a mechanism like https://github.com/Qiskit/documentation/issues/719.
