Fix sphinx warnings

4 jobs for new-changes in 8 minutes and 41 seconds (queued for 7 seconds)
Status Job ID Name Coverage
  Build
passed #187121
docker
build_linux_36

00:08:37

43.0%
passed #187122
docker
build_linux_37

00:08:32

43.0%
passed #187119
macosx
build_macosx_36

00:08:04

43.0%
passed #187120
macosx
build_macosx_37

00:07:50

43.0%