Adding README for the ps_is_instrument_default_enabled() function.

Author: JesperWisborgKrogh

README.md

@@ -1424,6 +1424,31 @@ mysql> SELECT sys.ps_is_account_enabled('localhost', 'root');
 1 row in set (0.01 sec)
 ```
 
+#### ps_is_instrument_default_enabled
+
+##### Description
+
+Returns whether an instrument is enabled 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_enabled('statement/sql/select');
++--------------------------------------------------------------+
+| sys.ps_is_instrument_default_enabled('statement/sql/select') |
++--------------------------------------------------------------+
+| YES                                                          |
++--------------------------------------------------------------+
+1 row in set (0.00 sec)
+```
+
 #### ps_thread_stack
 
 ##### Description