Apply suggestions from code review

Co-authored-by: Hugo van Kemenade <[email protected]>

peps/pep-9999.rst

@@ -99,7 +99,7 @@ all types of API users:
 * Create classes and instantiate them
 * Create instances of builtin and user-defined types
   and perform operations on them
-* Introspect objects, including types, instances, and functions.
+* Introspect objects, including types, instances, and functions
 * Raise and handle exceptions
 * Import modules
 * Manage threads
@@ -568,11 +568,11 @@ The behaviour of ``PySet_Contains`` is different from ``set.__contains__``
 [`Issue 6 <https://github.com/capi-workgroup/problems/issues/6>`__].
 
 The fact that ``PyArg_ParseTupleAndKeywords`` takes a non-const
-char* array as argument makes it more difficult to use.
+``char*`` array as argument makes it more difficult to use
 [`Issue 28 <https://github.com/capi-workgroup/problems/issues/28>`__].
 
-Python.h does not expose the whole API. Some headers (like marshal.h)
-are not included from Python.h.
+``Python.h`` does not expose the whole API. Some headers (like ``marshal.h``)
+are not included from ``Python.h``.
 [`Issue 43 <https://github.com/capi-workgroup/problems/issues/43>`__].
 
 
@@ -586,28 +586,28 @@ Debug Mode
 ~~~~~~~~~~
 
 A debug mode that can be activated without recompilation and which
-activates various checks that can help detect various types of errors.
+activates various checks that can help detect various types of errors
 [`Issue 36 <https://github.com/capi-workgroup/problems/issues/36>`__].
 
 Introspection
 ~~~~~~~~~~~~~
 
 There aren't currently reliable introspection capabilities for objects
-defined in C in the same way as there are for Python objects.
+defined in C in the same way as there are for Python objects
 [`Issue 32 <https://github.com/capi-workgroup/problems/issues/32>`__].
 
 Efficient type checking for heap types, similar to what ``Py*_Check``
-can do for a static type.
+can do for a static type
 [`Issue 17 <https://github.com/capi-workgroup/problems/issues/17>`__].
 
 Improved Interaction with Other Languages
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Interfacing with other GC based languages, and integrating their
-GC with Python's GC.
+GC with Python's GC
 [`Issue 19 <https://github.com/capi-workgroup/problems/issues/19>`__].
 
-Inject foreign stack frames to the traceback.
+Inject foreign stack frames to the traceback
 [`Issue 18 <https://github.com/capi-workgroup/problems/issues/18>`__].
 
 Concrete strings that can be used in other languages