add release note (#451)

Author: Intron7

docs/release-notes/0.13.3.md

@@ -7,6 +7,7 @@
 ```{rubric} Performance
 ```
 * make `dcg.aucell` faster using a single rank pass algorithm {pr}`448` {smaller}`S Dicks`
+* make FDR calculation faster and more scalable offering a new CPU and updated GPU path for `dcg`. {pr}`449` {smaller}`S Dicks`
 
 ```{rubric} Bug fixes
 ```