ZMO airframe: update parameters (#24803)

* ZMO airframe: update parameters

Including some parameters we found useful during the tests over the
previous months:

 - various controller & transition tuning refinements
 - remove battery capacity (not reliable enough w battery degradation)
 - airspeed scale
 - rotor configs:
    - remove everything related to rotors 3 and 4 (which don't exist)
    - set moment coefficients explicitly even if at default
 - Increase roll limit (FW_R_LIM, FD_FAIL_R)
 - min and max airspeeds
 - tilt servo min and default PWM values

* ZMO airframe: address review

 - explicitly set CA_ROTOR3_* to 0 (as these are set in the parent
   13100 which describes a quadrotor)
 - remove ASPD_SCALE_1 (close enough to default, and better to have
   slightly low reading)
 - remove MPC_ACC_HOR_MAX (= default)
 - remove MPC_TILTMAX_AIR (was temporary)
 - remove SENS_EN_SF1XX (= default)

* ZMO airframe: update tilt setup

to describe a setup where tilt servos can provide yaw torque in both
directions in multicopter mode.

* ZMO airframe: wording

docs/en/frames_vtol/vtol_tiltrotor_omp_hobby_zmo_fpv.md

@@ -332,7 +332,8 @@ If motors/servos were connected to different outputs than suggested, you will ne
 
    ![Tilt Servo adjustment](../../assets/airframes/vtol/omp_hobby_zmo_fpv/tilt-limits-01.jpg)
 
-1. Adjust the minimum or maximum value that the servo is pointing vertical up.
+1. Adjust the minimum (or, if revesed: maximum) value such that the rotor thrust can point backward (needed for proper yaw allocation in Multicopter mode).
+1. Adjust the parameter `VT_TILT_MC` such that the rotors point exactly upwards when given zero input.
 1. Then type `commander transition` into the MAVLink shell to adjust the horizontal position.
 
 #### Control Surfaces
@@ -361,8 +362,8 @@ The direction can't be changed in software because the vehicle does not use [DSh
 ## First Flight
 
 - Check tilt rotor reactions in [Stabilized mode](../flight_modes_fw/stabilized.md). Keep the throttle stick at the minimum and place the vehicle at the ground. To enable the tilt servos you need to arm the vehicle.
-  - Yaw the vehicle to the right (nose to the right) -> left motor should tilt down
-  - Yaw the vehicle to the left (nose to the left) -> right motor should tilt down
+  - Command a yaw to the right (nose to the right) -> left motor should tilt forward, right motor should tilt backward
+  - Command a yaw to the left (nose to the left) -> left motor should tilt backward, right motor should tilt forward
 - Mount the propellers.
 - Check center of gravity (GG).
   Switch the vehicle into forward flight mode.