add more Copter Throttle FS actions

Author: Hwurzburg

copter/source/docs/radio-failsafe.rst

@@ -76,6 +76,8 @@ The :ref:`FS_THR_ENABLE<FS_THR_ENABLE>` parameter can be set in the Mission Plan
 -  **Enabled Always Land** (Value 3) will switch the copter to Land Mode.
 -  **Enabled SmartRTL or RTL** (Value 4) will switch the copter to SmartRTL mode. If SmartRTL is not available, the copter will switch to RTL Mode instead.  If the GPS position is not usable, the copter will change to Land Mode instead.
 -  **Enabled SmartRTL or Land** (Value 5) will switch the copter to SmartRTL mode. If SmartRTL is not available, the copter will switch to Land Mode instead.
+-  **Enabled Auto DO_LAND_START or RTL** (value 6) will jump to the nearest "DO_LAND_START" mission item or RTL if no "DO_LAND_START" mission item has been programmed.
+-  **Enabled always Brake or Land** will BRAKE or LAND if GPS position is not available.
 -  Any invaild value (Such as accidentally enter 99 as a parameter value) will will behave the same as **Enabled Always LAND**
 
 The :ref:`FS_THR_VALUE<FS_THR_VALUE>`  parameter can be set in the Mission Planner full parameter list or full parameter tree, or can also be set using the Mission Planner *FS PWM* value in the Initial Setup >> Mandatory Hardware >> Failsafe menu.