Create release notes

Author: ReneKroon

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 2.10.0 (December 2021)
+
+#62 : @nikhilk1701 found a memory leak where removed items are not directly eligible for garbage collection. There are no API changes.
+
 # 2.9.0 (October 2021)
 
 #55,#56,#57 : @chenyahui was on fire and greatly improved the peformance of the library. He also got rid of the blocking call to expirationNotification, making the code run twice as fast in the benchmarks!