Fix the _PyGen_GetGeneratorFromFrame reference in the generators.md

Author: nybblista

InternalDocs/generators.md

@@ -30,7 +30,7 @@ The `frame` of a generator is embedded in the generator object struct as a
 [`_PyInterpreterFrame`](frames.md) (see `_PyGenObject_HEAD` in
 [`pycore_interpframe_structs.h`](../Include/internal/pycore_interpframe_structs.h)).
 This means that we can get the frame from the generator or the generator
-from the frame (see `_PyGen_GetGeneratorFromFrame` in the same file).
+from the frame (see `_PyGen_GetGeneratorFromFrame` in [`pycore_genobject.h`](../Include/internal/pycore_genobject.h)).
 Other fields of the generator struct include metadata (such as the name of
 the generator function) and runtime state information (such as whether its
 frame is executing, suspended, cleared, etc.).