Merge topic 'sphinx-docs'

0dddc427 Add release note
cc20328b docs: Update build instructions based on "build_windows_vs.md" document
d0360fc1 docs: Move original "coding_conventions.md" into the "docs" directory
63ac8ccf docs: Update and move content of "maint/gitlab.md" into "Release Process"
ba4e92a8 docs: Remove obsolete maint/release.md document
6fa24d52 docs: Update "Release Process" with distribution site to check for patches
0f82b6a1 docs: Include "Imported Third Party Projects" into developer guide
9bbd1b30 docs: ThirdParty/imported.md: Update list, add intro and update instructions
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Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Reviewed-by: Cory Quammen <cory.quammen@kitware.com>
Acked-by: David Gobbi <david.gobbi@gmail.com>
Merge-request: !10164