BLD: Explicitly request utf-8 encoding in docs conf.py (is default)
DOC: suppress warning during doc building
DOC: move _templates out of source/ files to avoid warning
DOC: disable running monkey patch example through ipython_directive

Makes line numbering break in following documents run through sphinx.
Very strange,
Merge pull request #5953 from y-p/PR_doc_fixes

Misc fixes to doc build