fix: Update API reference links from UWP to WinUI 3

hub/apps/design/accessibility/custom-automation-peers.md

@@ -461,6 +461,6 @@ More generally, be conservative with exceptions. Many clients cannot convert pro
 ## Related topics  
 * [Accessibility overview](accessibility-overview.md)
 * [XAML accessibility sample](https://github.com/microsoftarchive/msdn-code-gallery-microsoft/tree/411c271e537727d737a53fa2cbe99eaecac00cc0/Official%20Windows%20Platform%20Sample/XAML%20accessibility%20sample)
-* [**FrameworkElementAutomationPeer**](/uwp/api/Windows.UI.Xaml.Automation.Peers.FrameworkElementAutomationPeer)
-* [**AutomationPeer**](/uwp/api/Windows.UI.Xaml.Automation.Peers.AutomationPeer)
-* [**OnCreateAutomationPeer**](/uwp/api/windows.ui.xaml.uielement.oncreateautomationpeer)
+* [**FrameworkElementAutomationPeer**](/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.Automation.Peers.FrameworkElementAutomationPeer)
+* [**AutomationPeer**](/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.Automation.Peers.AutomationPeer)
+* [**OnCreateAutomationPeer**](/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.uielement.oncreateautomationpeer)

hub/apps/design/globalizing/adjust-layout-and-fonts--and-support-rtl.md

@@ -59,11 +59,11 @@ this.languageTag = Windows.Globalization.ApplicationLanguages.Languages[0];
 var flowDirectionSetting = Windows.ApplicationModel.Resources.Core.ResourceContext.GetForCurrentView().QualifierValues["LayoutDirection"];
 if (flowDirectionSetting == "LTR")
 {
-    this.layoutRoot.FlowDirection = Windows.UI.Xaml.FlowDirection.LeftToRight;
+    this.layoutRoot.FlowDirection = Microsoft.UI.Xaml.FlowDirection.LeftToRight;
 }
 else
 {
-    this.layoutRoot.FlowDirection = Windows.UI.Xaml.FlowDirection.RightToLeft;
+    this.layoutRoot.FlowDirection = Microsoft.UI.Xaml.FlowDirection.RightToLeft;
 }
 ```
 

hub/apps/design/globalizing/prepare-your-app-for-localization.md

@@ -82,7 +82,7 @@ When you install an app that contains localized language data, you might find th
 > [!NOTE]
 > It is not possible to install additional language support for your app after the initial installation. If you change the default language after installing an app, the app continues to use only the original language resources.
 
-If you want to ensure all language resources are available after installation, create a configuration file for the app package that specifies that certain resources are required during installation (including language resources). This optimized installation feature is automatically enabled when your application's .appxbundle is generated during packaging. For more information, see [Ensure that resources are installed on a device regardless of whether a device requires them](/previous-versions/dn482043(v=vs.140)).
+If you want to ensure all language resources are available after installation, create a configuration file for the app package that specifies that certain resources are required during installation (including language resources). This optimized installation feature is automatically enabled when your application's .appxbundle is generated during packaging. For more information, see [Create language resources](/windows/apps/windows-app-sdk/mrtcore/tailor-resources-lang-scale-contrast).
 
 Optionally, to ensure all resources are installed (not just a subset), you can disable .appxbundle generation when you package your app. This is not recommended however as it can increase the installation time of your app.
 
@@ -130,14 +130,17 @@ After strings are separated into resource files, they can be translated. The ide
 Consider these options.
 
 - **The resource files can be translated by opening them directly in the project.** This approach works well for a project that has a small volume of strings that need to be translated into two or three languages. It could be suitable for a scenario where a developer speaks more than one language and is willing to handle the translation process. This approach benefits from being quick, requires no tools, and minimizes the risk of mistranslations. But it is not scalable. In particular, the resources in different languages can easily get out of sync, causing bad user experiences and maintenance headaches.
-- **The string resource files are in XML or ResJSON text format, so could be handed off for translation using any text editor. The translated files would then be copied back into the project.** This approach carries a risk of translators accidentally editing the XML tags, but it lets translation work take place outside of the Microsoft Visual Studio project. This approach could work well for projects that need to be translated into a small number of languages. The XLIFF format is an XML format specifically designed for use in localization, and should be well supported by some localization vendors or localization tools. You can use the [Multilingual App Toolkit](/previous-versions/windows/apps/jj572370(v=win.10)) to generate XLIFF files from other resource files, such as .resw or .resjson.
+- **The string resource files are in XML or ResJSON text format, so could be handed off for translation using any text editor. The translated files would then be copied back into the project.** This approach carries a risk of translators accidentally editing the XML tags, but it lets translation work take place outside of the Microsoft Visual Studio project. This approach could work well for projects that need to be translated into a small number of languages. The XLIFF format is an XML format specifically designed for use in localization, and should be well supported by some localization vendors or localization tools. You can generate XLIFF files from resource files, such as .resw or .resjson, to support translation workflows.
+
+> [!NOTE]
+> The Multilingual App Toolkit (MAT) is no longer actively maintained. For localization and translation workflows, consider using modern localization services like Azure Cognitive Services or other third-party translation platforms.
 
 > [!NOTE]
 > Localization might also be necessary for other assets, including images and audio files.
 
 You should also consider the following:
 
-- **Localization tools** A number of localization tools are available for parsing resource files and allowing only the translatable strings to be edited by translators. This approach reduces the risk of a translator accidentally editing the XML tags. But it has the drawback of introducing a new tool and process to the localization process. A localization tool is good for projects with a large volume of strings but a small number of languages. To learn more, see [How to use the Multilingual App Toolkit](/previous-versions/windows/apps/jj572370(v=win.10)).
+- **Localization tools** A number of localization tools are available for parsing resource files and allowing only the translatable strings to be edited by translators. This approach reduces the risk of a translator accidentally editing the XML tags. But it has the drawback of introducing a new tool and process to the localization process. A localization tool is good for projects with a large volume of strings but a small number of languages. Modern alternatives to the deprecated Multilingual App Toolkit include various cloud-based localization platforms and services.
 - **Localization vendors** Consider using a localization vendor if your application contains extensive strings that need to be translated into a large number of languages. A localization vendor can give advice about tools and processes, as well as translating your resource files. This is an ideal solution, but is also the most costly option, and may increase the turnaround time for your translated content.
 
 ## Keep access keys and labels consistent