Add Changelog

Signed-off-by: Tushar Goel <tushar.goel.dav@gmail.com>

Author: TG1999

CHANGELOG.rst

@@ -5,6 +5,8 @@ next release
 ---------------------
 
 - WARNING: Vulnerablecode V1 API and UI has stopped supporting Ubuntu OVAL advisories, please shift to V3 API for new Ubuntu advisories.
+- WARNING: We will deprecate improver pipelines for calculating package version rank, grouping advisories for packages and calculating risk scores in the next release, we are doing it at advisory import time instead of as separate pipelines, this will improve the performance and consistency of the data.
+- Calculate package verion rank, group advisories for packages and package risk score and advisory risk score during import of advisories.
 - Add attribute ``pipeline_id`` to AdvisoryV2 to track the pipeline that created the advisory, also rename existing ``datasource_id`` and AVIDs. 
 
 Version v38.6.0