inserted update in RELEASE-NOTES

Author: shkr

RELEASE-NOTES.md

@@ -7,7 +7,8 @@
 
 - Improve NUTS initialization `advi+adapt_diag_grad` and add `jitter+adapt_diag_grad` (#2643) 
 - Update loo, new improved algorithm (#2730)
-
+- New CSG (Constant Stochastic Gradient) approximate posterior sampling
+  algorithm added
 ### Fixes 
 - Fixed `compareplot` to use `loo` output. 
 - Add test for `model.logp_array` and `model.bijection` (#2724) 
@@ -249,6 +250,7 @@ Patricio Benavente <[email protected]>
 Raymond Roberts
 Rodrigo Benenson <[email protected]>
 Sergei Lebedev <[email protected]>
+Shashank Shekhar <[email protected]>
 Skipper Seabold <[email protected]>
 Thomas Kluyver <[email protected]>
 Tobias Knuth <[email protected]>