Update readthedocs for version 5

[dgilmanAIDENTIFIED]

The version 5 changelog is not on readthedocs

[benkonrath]

It looks like the docs aren't automatically publishing to readthedocs anymore. I'll look into this.

[benkonrath]

Thanks for reporting the problem.

The 5.0 docs are now on readthedocs on the default "latest" alias. The "stable" alias can't be built until we make a new release. It looks like at some point a .readthedocs.yml config file was added as a requirement to build and publish the docs, and that config file is not in the 5.0 tagged tree.

I don't think it's worth a new release just for this problem, but I'll try to make a new release a little faster than the last one.

I'll keep this issue open as a reminder.