Documented PySequence_List() and PySequence_Tuple().
Documented PySequence_List() and PySequence_Tuple().

Added a bit more documentation in the chapter on building extension types,
including Py_FindMethod() documentation.

Several minor consistency nits were fixed.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator