Mention AST unchanged

Author: joshuabambrick

peps/pep-0736.rst

@@ -520,7 +520,8 @@ Reference Implementation
 
 `A proposed implementation <https://github.com/Hels15/cpython/tree/last-build>`_
 for cpython has been provided by @Hels15. We will extend this implementation to
-add an AST node attribute indicating for keywords whether the value was elided.
+add an AST node attribute indicating for keywords whether the value was elided,
+but otherwise the AST will remain unchanged.
 
 References
 ==========