gh-71616: Add note to warn against general translation of saxutils.escape() (#93450)

* Add note to warn against general translation of saxutils.escape()

* Use more direct wording

Author: slateny

Doc/library/xml.sax.utils.rst

@@ -25,6 +25,11 @@ or as base classes.
    replaced with its corresponding value.  The characters ``'&'``, ``'<'`` and
    ``'>'`` are always escaped, even if *entities* is provided.
 
+   .. note::
+
+      This function should only be used to escape characters that
+      can't be used directly in XML. Do not use this function as a general
+      string translation function.
 
 .. function:: unescape(data, entities={})