CMake: Add global / top-level docs targets

Previously you could use either module-specific or
repo-specific 'docs' targets.
For example 'ninja html_docs_qtbase' or 'ninja html_docs_Core'.

Now there's a global / top-level target called
'docs', so 'ninja docs' works.

For super builds it will build the documentation of all
configured repositories.

For a single repo build, it's equivalent to calling
'ninja docs_repo_name'.

Also for consistency, add the "docs_Core" target, which was missing
before. So now a 'docs' target exsits for repo names AND targets.

New global target names are
- docs
- prepare_docs
- generate_docs
- html_docs
- qch_docs
- install_html_docs_docs
- install_qch_docs_docs
- install_docs_docs

Amends 0095ff4e0659906595d281b37c3b7f89e37250af

Change-Id: I686be1e0962e40cbce860e8ac2cabb056b360ac2
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

0 files changed, 0 insertions, 0 deletions