Added note about breaking changes in 10.0.0 (#467)

* Update CHANGELOG.md

---------

Co-authored-by: Alexander Batishchev <[email protected]>

Author: cmeeren

CHANGELOG.md

@@ -14,10 +14,12 @@
 
 # 10.0.0
 
+- **Breaking:** Made System.Text.Json the default serializer on the platforms where it's available
+- **Breaking:** Made verify=true by default in IJwtDecoder methods
+
 - Made NoneAlgorithm not requiring any keys as it is not signed
 - Added option to select default serializer, Newtonsoft.Json or System.Text.Json (#433)
 - Renamed default IdentityFactory in Jwt.Extensions.AspNetCore, opened up for inheritance, extension (#428)
 - Added Encode(T) and Encode(Type, object) to JwtBuilder (#415)
 - Updated Newtonsoft.Json to version 13.0.1
 - Fixed typos in exception messages
-- Made verify=true by default in IJwtDecoder methods