Let's document the method to build docs but only rebuild one or a few files likemake -C Doc html SOURCES=<path>, it can be much quicker than rebuilding the whole set.

For example:

• make -C Doc html SOURCES=whatsnew/3.13.rst
• make -C Doc html SOURCES="whatsnew/3.13.rst whatsnew/3.12.rst" (double check this syntax)

And I think it might be Unix only?