Update abstract

Author: Aloqeely

web/pandas/pdeps/0017-backwards-compatibility-and-deprecation-policy.md

@@ -10,6 +10,10 @@
 
 This PDEP defines pandas' backwards compatibility and deprecation policy.
 
+The main additions to [pandas' current version policy](https://pandas.pydata.org/pandas-docs/version/2.2/development/policies.html) are:
+- Deprecated functionality should remain unchanged in at least 2 minor releases
+- Deprecations should initially use DeprecationWarning, and then be switched to FutureWarning in the last minor release before the major release they are planned to be removed in
+
 ## Motivation
 
 Having a clear backwards compatibility and deprecation policy is crucial to having a healthy ecosystem. We want to ensure users can rely on pandas being stable while still allowing the library to evolve.