doc: reef 18.2.5 release notes

https://tracker.ceph.com/issues/7056

Signed-off-by: Yuri Weinstein <[email protected]>

Author: Yuri Weinstein

doc/releases/index.rst

@@ -72,6 +72,7 @@ Release timeline
 .. _18.2.1: reef#v18-2-1-reef
 .. _18.2.2: reef#v18-2-2-reef
 .. _18.2.4: reef#v18-2-4-reef
+.. _18.2.5: reef#v18-2-5-reef
 
 .. _Quincy: quincy
 .. _17.2.0: quincy#v17-2-0-quincy