docs/features: add screenshot of testing UI

And remove the old announcement about dlv-dap transition.

Change-Id: Ia0996932223fc79482052797835b8c992dcb8520
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/350142
Trust: Hyang-Ah Hana Kim <[email protected]>
Run-TryBot: Hyang-Ah Hana Kim <[email protected]>
TryBot-Result: kokoro <[email protected]>
Reviewed-by: Ethan Reesor <[email protected]>
Reviewed-by: Suzy Mueller <[email protected]>

Author: hyangah

README.md

@@ -9,8 +9,6 @@ provides rich language support for the
 [Go programming language](https://golang.org/).
 
 
-> 📣 Debugging using [`Delve`'s native DAP implementation](https://github.com/golang/vscode-go/blob/master/docs/debugging.md) is enabled by default in v0.27.0.<br>
-
 ## Quick Start
 
 Welcome! 👋🏻<br/>

docs/features.md

@@ -203,7 +203,9 @@ Behind the scenes, the `Debug: Start without Debugging` command calls `go run`.
 
 ### Test and benchmark
 
-[Code lenses](https://code.visualstudio.com/blogs/2017/02/12/code-lens-roundup) allow users to easily run tests and benchmarks for a given function, file, package, or workspace. Alternatively, the same functionality is available through a set of commands: [`Go: Test Function At Cursor`](commands.md#go-test-function-at-cursor), [`Go: Test File`](commands.md#go-test-file), [`Go: Test Package`](commands.md#go-test-package), and [`Go: Test All Packages in Workspace`](commands.md#go-test-all-packages-in-workspace).
+[Test UI](https://code.visualstudio.com/api/extension-guides/testing) and [Code lenses](https://code.visualstudio.com/blogs/2017/02/12/code-lens-roundup) allow users to easily run tests and benchmarks for a given function, file, package, or workspace. Alternatively, the same functionality is available through a set of commands: [`Go: Test Function At Cursor`](commands.md#go-test-function-at-cursor), [`Go: Test File`](commands.md#go-test-file), [`Go: Test Package`](commands.md#go-test-package), and [`Go: Test All Packages in Workspace`](commands.md#go-test-all-packages-in-workspace).
+
+<div style="text-align: center;"><img src="images/testexplorer.gif" alt="Testing UI" style="width: 75%"> </div>
 
 ### Code Coverage