Improve documentation by preserving paragraphs in the
nm-settings-nmcli man pages.
To do that structure of src/libnm-client-impl/nm-settings-docs-gir.xml
was changed to have "description" as subnode to property node instead
of attribute of property node. Another subnode "description-docbook"
was added - this node is then used when generating man pages.
tools/generate-docs-nm-settings-docs-gir.py and man/nm-settings-dbus.xsl
were also changed to accomodate for changes mentioned above.
Replace xsltproc tool with python script when generating
./src/libnmc-setting/settings-docs.h.
Deleted settings-docs.xsl since it was replaced by python script.
Change src/libnmc-setting/settings-docs.h.in accodring to newly
generated src/libnmc-setting/settings-docs.h
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/661https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1260
