DOC: Update performance comparison section of io docs
xref https://github.com/python-sprints/pandas-mentoring/issues/163

Hi Marc @datapythonista  Hi Marc @datapythonista .
Kindly check this PR? I restored the indentation for a moment, to have an easier diff (but can undo that in the end, as a 4-space indent is easier to work with) lgtm. @jorisvandenbossche  @WuraolaOyewusi can you fix up the merge conflict? I think we can merge this in once complete @WillAyd 
Done Great thanks @WuraolaOyewusi keep em coming