Update readme and announcements for 17.9

README.md

@@ -98,6 +98,24 @@ You can find a Visual Studio solution that contains all samples at [Samples.sln]
 | [Project Query](New_Extensibility_Model/Samples/VSProjectQueryAPISample) | Shows several different kinds of project system queries you can make. |
 | [Comment remover](New_Extensibility_Model/Samples/CommentRemover) | Shows how to consume [Visual Studio SDK](https://www.nuget.org/packages/Microsoft.VisualStudio.SDK) services through .NET dependency injection and use VisualStudio.Extensibility APIs for commands, prompts, and progress report.|
 
+## Experimental APIs and Breaking Changes
+Starting with our 17.9 release, we're ready to label the vast majority of our APIs as stable. That is, we don't plan to make any breaking changes to these APIs. Any breaking changes that might need to be made, for example in response to user feedback about usability, will be communicated formally and with plenty of notice on our [breaking changes](./docs/breaking_changes.md) page.
+
+There are a few of our APIs that don't yet meet this bar for stability, for one of several reasons:
+* The feature area is new and additional features and changes are expected in future versions.
+* The API is new and we want to incorporate user feedback into the deisgn before marking it stable.
+* We've received feedback that a particular API is difficult to use, so we're planning on updating it in future versions.
+
+For these APIs, we've explicitly labeled them using the `[Experimental]` attribute to help extension authors create their extensions with confidence in the the SDK.
+
+For more information, including how to use experimental APIs, please see our [Experimental APIs](./docs/experimental_apis.md) page.
+
+## Known Issues
+
+We appreciate your feedback and bug reports in our [Issues Tracker](https://github.com/microsoft/VSExtensibility/issues), and we work to address any issues found in the SDK.
+
+Please visit our [Known Issues](./docs/known_issues.md) page for information about any current known issues.
+
 ## Advanced Topics
 
 | Article | Description|

docs/announcements.md

@@ -24,3 +24,19 @@ Use this page to stay up-to-date on all upcoming extensibility announcements and
 
 ## August 10, 2022
 * [VisualStudio.Extensibility phase 2](https://devblogs.microsoft.com/visualstudio/visualstudio-extensibility/) is released publicly adding more extensibility feature areas.
+
+## February 20, 2024
+We've released updated packages and templates starting with the Visual Studio 2022 17.9 official release. This version adds the following new features:
+* Create VSIX packages that can be shared with other users and published to the Visual Studio Marketplace
+* Install VisualStudio.Extensibility-based extensions without restarting Visual Studio
+* Configure your extensions in-code with updated configuration properties
+* Create dockable/non-modal debugger visualizers
+* Leverage your LSP servers in your extensions
+* Query the project system with an enhanced query API.
+
+To learn more, please see our [announcement on the Visual Studio blog](https://devblogs.microsoft.com/visualstudio/visualstudio-extensibility-17-9/).
+
+In addition, we've also formalized our stability model for our APIs, and added the following new pages:
+* [Known Issues](./known_issues.md) - lists known issues with the VisualStudio.Extensibility SDK.
+* [Experimental APIs](./experimental_apis.md) - lists APIs that are considered experimental/non-stable and describes how to use them.
+* [Breaking Changes](./breaking_changes.md) - lists APIs that have had breaking changes since the previous release.