Adding README for the ps_is_instrument_default_timed() function.

Author: JesperWisborgKrogh

README.md

@@ -1449,6 +1449,31 @@ mysql> SELECT sys.ps_is_instrument_default_enabled('statement/sql/select');
 1 row in set (0.00 sec)
 ```
 
+#### ps_is_instrument_default_timed
+
+##### Description
+
+Returns whether an instrument is timed by default in this version of MySQL.
+
+##### Parameters
+
+* in_instrument VARCHAR(128): The instrument to check.
+
+##### Returns
+
+ENUM('YES', 'NO')
+
+##### Example
+```SQL
+mysql> SELECT sys.ps_is_instrument_default_timed('statement/sql/select');
++------------------------------------------------------------+
+| sys.ps_is_instrument_default_timed('statement/sql/select') |
++------------------------------------------------------------+
+| YES                                                        |
++------------------------------------------------------------+
+1 row in set (0.00 sec)
+```
+
 #### ps_thread_stack
 
 ##### Description