Merge topic 'consolidate-markdown-files-into-docs'

1cdbb599 docs: Fix invalid figure options in VTKFileFormats.md
080bef42 docs: Fix missing reference warning in ModuleSystem.md
77cccfb2 docs: Consolidate "Advanced Topics" and "API" documents
242ea235 docs: Consolidate "Design documents" files
5000c907 docs: Consolidate "Build instructions" documents
5d5c273f docs: Consolidate "Developer's Guide" documents
cca23eb8 docs: Simplify generation removing need for manual substitutions

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Reviewed-by: Christos Tsolakis <christos.tsolakis@kitware.com>
Merge-request: !10281