Add geoview controller readme doc

Added doc for GeoViewController

Author: pMaske

README.md

@@ -24,6 +24,7 @@ The ArcGIS Maps SDK for .NET Toolkit contains controls and components to acceler
 | [Compass](docs/compass.md) | ![compass](https://user-images.githubusercontent.com/1378165/73389839-d9c8f500-4289-11ea-923c-18232489b3e0.png) | Show a compass direction when the map or scene is rotated. | WinUI, MAUI, UWP, WPF |
 | [FeatureDataField](docs/feature-data-field.md)   | ![FeatureDataField](https://user-images.githubusercontent.com/1378165/73389879-ebaa9800-4289-11ea-8e4e-de153a6a371a.png) | Display and optionally allow editing of a single field attribute of a feature. | UWP, WPF |
 |[FloorFilter](docs/floor-filter.md) | ![image](https://user-images.githubusercontent.com/29742178/158746908-71a39e28-596f-44b6-9230-e2a04bdaeb9e.png) | Browse floor-aware maps and scenes and filter the view to show levels in a facility. | WinUI, MAUI, UWP, WPF |
+|[GeoViewController](docs/geoviewcontroller.md) | | A helpfer class to enable easy adoption of MVVM patterns in an ArcGIS Maps SDK for .NET application. | WinUI, MAUI, UWP, WPF |
 | [Legend](docs/legend.md)   | <img src="https://user-images.githubusercontent.com/1378165/73389924-011fc200-428a-11ea-91bf-4ea1c2bf6683.png" width="105" title="Legend" />| Display a legend for a map or scene view. | WinUI, MAUI, UWP, WPF |
 | [MeasureToolbar](docs/measure-toolbar.md)  | ![MeasureToolbar](https://user-images.githubusercontent.com/1378165/73389958-0f6dde00-428a-11ea-8c78-7192d49ea605.png) | Measure distances, areas, and features in a map view. | UWP, WPF |
 |[OverviewMap](docs/overview-map.md) | <img src="https://user-images.githubusercontent.com/29742178/121975740-34f07000-cd37-11eb-9162-462925cb3fe7.png" width="150" title="Overview Map" /> | Display an interactive inset map for a map or scene. | WinUI, MAUI, UWP, WPF |

docs/controls.md

@@ -32,6 +32,10 @@ Browse floor-aware maps and scenes and filter the view to show levels in a facil
 
 ![FloorFilter](https://user-images.githubusercontent.com/29742178/158746908-71a39e28-596f-44b6-9230-e2a04bdaeb9e.png)
 
+### GeoViewController
+
+A helper class for enabling easy adoption of MVVM patterns in ArcGIS Maps SDK for .NET applications. 
+
 ### Legend
 
 Displays a legend for a map or scene view.
@@ -100,6 +104,7 @@ Use named trace configurations defined in a web map to perform connected trace o
 |[Compass](compass.md)   | ✔ | ✔ | ✔ |
 |[FeatureDataField](feature-data-field.md)   | ✔ | ✔ | ❌ |
 |[FloorFilter](floor-filter.md) | ✔  | ✔ | ✔ |
+|[GeoViewController](geoviewcontroller.md | ✔  | ✔ | ✔ |
 |[Legend](legend.md)   | ✔ | ✔ | ✔ |
 |[MeasureToolbar](measure-toolbar.md)   | ✔ | ✔ | ❌ |
 |[OverviewMap](overview-map.md) | ✔ | ✔ | ✔ |

docs/geoviewcontroller.md

@@ -0,0 +1,25 @@
+# GeoViewController
+
+GeoViewController is a helper class for enabling easy adoption of MVVM patterns in ArcGIS Maps SDK for .NET applications. 
+The helper class allows you to perform view operations on the MapView from your ViewModel, through an attached proxy-object that ensures you keep ViewModel and View separated.
+
+![geoviewcontroller](https://user-images.githubusercontent.com/1378165/73389839-d9c8f500-4289-11ea-923c-18232489b3e0.png)
+
+## Features
+
+- GeoViewController class can manage most common `GeoView` operations like setting viewpoint, performing identify and showing callouts. Any specific `MapView` or `SceneView` operations are not accessible via this helper class.
+- The helper class is extensible. You can add your own custom map and scene operations, or interface for enabling testing (see WPF sample).
+
+## Usage
+
+```xml
+<esri:MapView x:Name="MyMapView"
+              Map="{Binding Map, Source={StaticResource VM}}"
+              esri:GeoViewController.GeoViewController="{Binding Controller, Source={StaticResource VM}}">
+            <Behaviors:Interaction.Triggers>
+                <Behaviors:EventTrigger EventName="GeoViewTapped" >
+                    <Behaviors:InvokeCommandAction Command="{Binding GeoViewTappedCommand, Source={StaticResource VM}}" PassEventArgsToCommand="True" />
+                </Behaviors:EventTrigger>
+            </Behaviors:Interaction.Triggers>
+        </esri:MapView>
+```