CHANGELOG: added info on new API for iteration over JSON object

Change-Id: Ia82a6a5315e430e22cd0cec471ff45a5f5458eec
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/431201
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>

CHANGELOG.md

@@ -148,6 +148,16 @@ devices.
 
 spdk_file_get_id() returning unique ID for the file was added.
 
+### JSON
+
+Added API enabling iteration over JSON object:
+ - spdk_json_find()
+ - spdk_json_find_string()
+ - spdk_json_find_array()
+ - spdk_json_object_first()
+ - spdk_json_array_first()
+ - spdk_json_next()
+
 ## v18.07:
 
 ### bdev