Now that all sphinx warnings have been fixed by @vlorentz, it would
be great to avoid introducing new ones as much as possible.
This diff showcases how a sphinx environment can be added to tox
to build and check the documentation proper to a swh package.
As some external references could not be resolved in a single package
scope, related sphinx warnings are suppressed for the build to succeed
but other ones are not.
This would allow to catch any rst errors prior landing a diff.
Ideally a new parallel step in our Jenkins pipelines to build and
check the doc should be added. We already have a CI docker image
containing all the required tools to build the doc so this should
not be too complicated to integrate.
Depends on D5571
Could you also explain this is used on the CI because it does not have ../swh-docs/?