Links to changelogs in releases don't work

[susilehtola]

The links to the changelogs on the GitHub releases page don't work.

For example, for 0.26.0, the changelog link is given as
https://github.com/MolSSI/QCElemental/blob/master/docs/source/changelog.rst#0260--2023-07-31

which gives a 404 - page not found. The correct link is obtained by removing source/:
https://github.com/MolSSI/QCElemental/blob/master/docs/changelog.rst#0260--2023-07-31

[loriab]

drat, I must have copied the pattern from qcengine, which does have a source/ in there.

[loriab]

Ah, #310 removed the source/ intermediate dir. Ok, I've fixed the latest two in the GH releases links and will go through the rest.