Fix several C-API doc typos caught by tomo cocoa on docs@.

The signature and description of PyException_SetCause now use "cause"
rather than "ctx" to match the code.
diff --git a/Doc/c-api/module.rst b/Doc/c-api/module.rst
index e80e0ea..bd46170 100644
--- a/Doc/c-api/module.rst
+++ b/Doc/c-api/module.rst
@@ -113,7 +113,7 @@
 
    Return a pointer to the :c:type:`PyModuleDef` struct from which the module was
    created, or *NULL* if the module wasn't created with
-   :c:func:`PyModule_Create`.i
+   :c:func:`PyModule_Create`.
 
 .. c:function:: PyObject* PyState_FindModule(PyModuleDef *def)