DOC/BLD: squash annoying sphinx bugs

[cpcloud]

carrying over from #3720

these sphinx bugs WILL be squashed!!

• lookup
• to_csv (there's a newline character here that's causing the issue. that i'm trying to figure out how to escape it in sphinx) duh use raw strings
• ExcelFile.parse
• read_excel
• docscrape.py: Unknown Section Example
• docscrape.py: Unknown Section Optional Parameters

moral of the story: when writing docstrings please follow the sphinx rules to a tee!

[cpcloud]

take that sphinx