doc(release): prepare release notes for 2021-Q4 release (v1.3)

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

CHANGELOG.md

 # RELEASE NOTES: #
 
+## v1.3.0 -- January 2022 ##
+
+* Added HTTP2 support
+* Fix build issue
+* Fix static addr allocation
+* Docker build optimizations
+
 ## v1.2.1 -- October 2021 ##
 
 * Fix build issue