[docs] [issue8925] Improve c-api/arg.rst: use "bytes" or "str" types instead of "string"

Georg Brandl <georg@python.org> added the comment: The glossary (see docs.python.org/glossary) does not have an entry for "buffer interface" or "buffer protocol". An index entry just means that some location in the code defines this entry and gets a link back. Of course, you can also link to the C API section using :ref:`bufferobjects`. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue8925> _______________________________________