v20.3.0
doc/radosgw: update QAT acceleration to specify the configuration
doc/install: update "update submodules"
doc/install: update "Official Releases" sources
documentation: Update get-packages.rst
doc: update canonical tarballs URL
docs: Add information about OpenNebula integration
doc/install/index_manual: remove cephadm from toctree
doc/install: add prompts to install-storage-cluster
doc: use plantweb as fallback of sphinx-ditaa
doc/install: Keep the name field of the created user consistent with the node name in the Start RADOSGW service command
doc/install: Remove Upstart from Freebsd deployment
doc: Remove inactive Ceph mirrors.
doc: reorganize Windows docs
doc: Document the Windows CI job
doc,man: typos found by codespell