Added screenshots

Author: Michael Hoffman

GettingStartedGuides/WPF_GettingStarted/README.md

@@ -11,3 +11,5 @@ urlFragment: WPF_GettingStarted
 
 <!-- only enough info to differentiate this sample vs the others; what is different about this sample compared to the sibling samples? -->
 This sample, **WPF_GettingStarted**, is the completed Visual Studio project that results from following the steps in the tutorial [Get started with WebView2 in WPF apps](https://docs.microsoft.com/microsoft-edge/webview2/get-started/wpf).
+
+![The running app from the finished WinUI 3 (Windows App SDK) tutorial](screenshots/wpf-getting-started-bing.png)

GettingStartedGuides/WPF_GettingStarted/screenshots/wpf-getting-started-bing.png

@@ -11,3 +11,5 @@ urlFragment: Win32_GettingStarted
 
 <!-- only enough info to differentiate this sample vs the others; what is different about this sample compared to the sibling samples? -->
 This sample, **Win32_GettingStarted**, is the completed Visual Studio project that results from following the steps in the tutorial [Get started with WebView2 in Win32 apps](https://docs.microsoft.com/microsoft-edge/webview2/get-started/win32).
+
+![The running app from the finished Win32 tutorial](screenshots/bing-window.png)

GettingStartedGuides/Win32_GettingStarted/README.md

@@ -11,3 +11,5 @@ urlFragment: WinForms_GettingStarted
 
 <!-- only enough info to differentiate this sample vs the others; what is different about this sample compared to the sibling samples? -->
 This sample, **WinForms_GettingStarted**, is the completed Visual Studio project that results from following the steps in the tutorial [Get started with WebView2 in WinForms apps](https://docs.microsoft.com/microsoft-edge/webview2/get-started/winforms).
+
+![The running app from the finished WinForms tutorial](screenshots/winforms-bing.png)

GettingStartedGuides/Win32_GettingStarted/screenshots/bing-window.png

@@ -11,3 +11,5 @@ urlFragment: WinUI3_GettingStarted
 
 <!-- only enough info to differentiate this sample vs the others; what is different about this sample compared to the sibling samples? -->
 This sample, **WinUI3_GettingStarted**, is the completed Visual Studio project that results from following the steps in the tutorial [Get started with WebView2 in WinUI 3 (Windows App SDK) apps](https://docs.microsoft.com/microsoft-edge/webview2/get-started/winui).
+
+![The running app from the finished WinUI 3 (Windows App SDK) tutorial](screenshots/getting-started-part-3.png)

GettingStartedGuides/WinForms_GettingStarted/README.md

@@ -21,4 +21,4 @@ This sample, **WV2CDPExtensionWPFSample**, is built with the WebView2 CDP Extens
 
 To use this sample, see [WPF sample app with CDP extension](https://docs.microsoft.com/microsoft-edge/webview2/samples/wv2cdpextensionwpfsample).
 
-![CDP Extension sample app running](screenshots/cdp-extension-sample-app-running.png)
+![CDP Extension sample app running](screenshots/wv2cdpextensionwpfsample-app-running.png)