Merge pull request #3754 from mdboom/freetype-not-optional

DOC/MNT : Freetype isn't actually optional
DOC : add style module to generated docs

Closes #3705
Merge pull request #3856 from tacaswell/style_doc

DOC : add style module to generated docs
Merge remote-tracking branch 'refs/remotes/upstream/v1.4.2-doc' into v1.4.x