doc update for gimble stabilization

docs/image_apis.md

@@ -161,6 +161,8 @@ To change orientation of individial camera, you can use `setCameraOrientation` A
 client.setCameraOrientation(0, AirSimClientBase.toQuaternion(0.261799, 0, 0)); #radians
 ```
 
+You can set stabilization for pitch, roll or yaw for any camera [using settings](settings.md#gimble).
+
 Please see [example usage](https://github.com/Microsoft/AirSim/blob/master/PythonClient/cv_mode.py).
 
 ## Changing Resolution and Camera Parameters

docs/settings.md

@@ -156,6 +156,7 @@ For explanation of other settings, please see [this article](https://docs.unreal
 
 The `ImageType` element determines which image type the settings applies to. The valid values are described in [ImageType section](image_apis.md#available-imagetype). In addition, we also support special value `ImageType: -1` to apply the settings to external camera (i.e. what you are looking at on the screen).
 
+### Gimble
 The `Gimble` element allows to freeze camera orientation for pitch, roll and/or yaw. This setting is ignored unless `ImageType` is -1. The `Stabilization` is defaulted to 0 meaning no gimble i.e. camera orientation changes with body orientation on all axis. The value of 1 means full stabilization. The value between 0 to 1 acts as a weight for fixed angles specified (in degrees, in world-frame) in `Pitch`, `Roll` and `Yaw` elements and orientation of the vehicle body. When any of the angles is ommitted from json or set to NaN, that angle is not stabilized (i.e. it moves along with vehicle body).
 
 Note that `CaptureSettings` element is json array so you can add settings for multiple image types easily.