Add an inheritable warning to the base Estimator class.

With this change the doc generator will add the warning to any subclass of Estimator, in any project on tensorflow.org the next time that their doc-generator is run.

PiperOrigin-RevId: 383739212
Change-Id: I3a513362ae31b83301aaa339566495048fe063b3

tensorflow/tools/docs/doc_controls.py

@@ -32,6 +32,18 @@ def set_deprecated(obj: T) -> T:
   return obj
 
 
+_INHERITABLE_HEADER = "_tf_docs_inheritable_header"
+
+
+def inheritable_header(text):
+
+  def _wrapped(cls):
+    setattr(cls, _INHERITABLE_HEADER, text)
+    return cls
+
+  return _wrapped
+
+
 _DO_NOT_DOC = "_tf_docs_do_not_document"