DOCS-2032: Add camera and gantry example snippets (#226)

lib/src/components/camera/camera.dart

@@ -12,12 +12,24 @@ abstract class Camera extends Resource {
   static const Subtype subtype = Subtype(resourceNamespaceRDK, resourceTypeComponent, 'camera');
 
   /// Get the next image from the camera.
+  ///
+  /// ```
+  /// var nextImage = await myCamera.image();
+  /// ```
   Future<ViamImage> image({MimeType? mimeType, Map<String, dynamic>? extra});
 
   /// Get the next point cloud from the camera.
+  ///
+  /// ```
+  /// var nextPointCloud = await myCamera.pointCloud();
+  /// ```
   Future<ViamImage> pointCloud({Map<String, dynamic>? extra});
 
   /// Get the camera's intrinsic parameters and the camera's distortion parameters.
+  ///
+  /// ```
+  /// var cameraProperties = await myCamera.properties();
+  /// ```
   Future<CameraProperties> properties();
 
   /// Get the [ResourceName] for this [Camera] with the given [name]

lib/src/components/gantry/gantry.dart

@@ -6,22 +6,46 @@ import '../../robot/client.dart';
 abstract class Gantry extends Resource {
   static const Subtype subtype = Subtype(resourceNamespaceRDK, resourceTypeComponent, 'gantry');
 
-  /// Get the position of the axes in millimeters
+  /// Get the position of the axes in millimeters.
+  ///
+  /// ```
+  /// var position = await myGantry.position();
+  /// ```
   Future<List<double>> position({Map<String, dynamic>? extra});
 
-  /// Move the gantry to a new position in millimeters at the requested speeds in millimeters/second
+  /// Move the gantry to a new position in millimeters at the requested speeds in millimeters/second.
+  ///
+  /// ```
+  /// await myGantry.moveToPosition([0.0, 20.5], [15, 15]);
+  /// ```
   Future<void> moveToPosition(List<double> positions, List<double> speeds, {Map<String, dynamic>? extra});
 
-  /// Run the homing sequence and return true if completed successfully
+  /// Run the homing sequence and return true if completed successfully.
+  ///
+  /// ```
+  /// var homed = await myGantry.home();
+  /// ```
   Future<bool> home({Map<String, dynamic>? extra});
 
-  /// Get the lengths of the axes of the gantry in millimeters
+  /// Get the lengths of the axes of the gantry in millimeters.
+  ///
+  /// ```
+  /// var lengths = await myGantry.lengths();
+  /// ```
   Future<List<double>> lengths({Map<String, dynamic>? extra});
 
-  /// Stop all motion of the [Gantry]. It is assumed the [Gantry] stops immediately
+  /// Stop all motion of the [Gantry]. It is assumed the [Gantry] stops immediately.
+  ///
+  /// ```
+  /// await myGantry.stop();
+  /// ```
   Future<void> stop({Map<String, dynamic>? extra});
 
-  /// If the [Gantry] is currently moving
+  /// Whether the [Gantry] is currently moving.
+  ///
+  /// ```
+  /// var moving = await myGantry.isMoving();
+  /// ```
   Future<bool> isMoving();
 
   /// Get the [ResourceName] for this [Gantry] with the given [name]