fix(doc): fix documenting bindings structure

Author: jkwlui

api_core/google/api_core/iam.py

@@ -171,15 +171,14 @@ def _contains_conditions(self):
     @property
     def bindings(self):
         """:obj:`list` of :obj:`dict`: The policy's bindings list.
-        :obj:`dict` Binding:
+
+        A binding is specified by a dictionary with keys:
             role (str): Role that is assigned to `members`.
             members (:obj:`set` of str): Specifies the identities associated to this binding.
             condition (dict of str:str): Specifies a condition under which this binding will apply.
-
-        :obj:`dict` Condition:
-            title (str): Title for the condition.
-            description (:obj:str, optional): Description of the condition.
-            expression: A CEL expression.
+                title (str): Title for the condition.
+                description (:obj:str, optional): Description of the condition.
+                expression: A CEL expression.
 
         See:
             Policy versions https://cloud.google.com/iam/docs/policies#versions