Update garbage_collector.rst

Author: pablogsal

garbage_collector.rst

@@ -403,8 +403,9 @@ The CPython GC makes use of two fat pointers:
   ``PREV_MASK_COLLECTING`` and ``_PyGC_PREV_MASK_FINALIZED``. Between collections,
   the only flag that can be present is ``_PyGC_PREV_MASK_FINALIZED`` that indicates
   if an object has been already finalized. During collections ``_gc_prev`` is
-  temporarily used for storing the temporarily copy of the reference count (``gc_refs``),
-  and the GC linked list becomes a singly linked list until ``_gc_prev`` is restored.
+  temporarily used for storing a copy of the reference count (``gc_refs``), in
+  addition to two flags, and the GC linked list becomes a singly linked list until
+  ``_gc_prev`` is restored.
 
 * The ``_gc_next`` field is used as the "next" pointer to maintain the doubly linked
   list but during collection its lowest bit is used to keep the