Include CHANGELOG.rst in source distribution?

[zklaus]

CHANGELOG.rst is read in setup.py, but not included in the source distribution.
This makes the source distribution not installable.

Possible solutions to this are either to include CHANGELOG.rst in the source distribution by adding it to MANIFEST.in or removing its use from setup.py. The latter is easy because it is read, but not actually used.

The reading of CHANGELOG.rst in setup.py follows the model of README.rst, but the difference is that the README is included in the source distribution by default, see here.

PS: I stumbled over this while packaging era5cli for conda-forge at conda-forge/staged-recipes#19321.