This change addresses the warnings and errors that are displayed when the
docs are built, including:
* Add reference to previously unreferenced workflow_extend in index file
* Remove reference to a _static directory that doesn't exist
* Fix formatting issues within the workflow_extend document
Comments in the bug report discuss the need for warnings to be treated
as errors, but this does not seem to be possible using the setup.py build_sphinx
command.
Change-Id: Iccccb9d104df9847ecd8a52aa73a7aa450bb5f34
Partial-Bug: #1411719
dbd907643f