docs: Add release notes for v5.1.0a2

DIRACGrid CI · DIRACGrid CI · commit 4ef8f5cf5cae · 2022-10-13T08:33:56.000Z
diff --git a/release.notes b/release.notes
@@ -1,3 +1,6 @@
+[v5.1.0a2]
+
+
 [v5.1.0a1]
 [v5.0.0]
 [v5.0.0a22]
