Work CI-CD

- Add pr-checks action.

***NO_CI***

.github/workflows/pr-checks.yml

@@ -0,0 +1,18 @@
+# Copyright (c) .NET Foundation and Contributors
+# See LICENSE file in the project root for full license information.
+
+name: PR Checks
+
+on:
+  pull_request:
+
+jobs:
+  check_package_lock:
+    name: nanoFramework
+    uses: nanoframework/nf-tools/.github/workflows/check-package-lock.yml@main
+  check_nuget_latest:
+    name: nanoFramework
+    uses: nanoframework/nf-tools/.github/workflows/check-packages-updated.yml@main
+    secrets: inherit
+    with:
+      solution: 'nanoFramework.System.Net.Sockets.UdpClient.sln'