Merge pull request #14364 from why-el/better-docs-for-update-attribute

Enhance docs for update_attribute [skip ci]

activerecord/lib/active_record/persistence.rb

@@ -214,6 +214,8 @@ def becomes!(klass)
     #
     # This method raises an +ActiveRecord::ActiveRecordError+  if the
     # attribute is marked as readonly.
+    #
+    # See also +update_column+.
     def update_attribute(name, value)
       name = name.to_s
       verify_readonly_attribute(name)