Add upgrade-nanoframework.sh

Make it easy to update to latest version.

Author: angularsen

upgrade-nanoframework.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Convenience script to update nanoFramework dependencies.
+declare -r SCRIPT_DIR=$(realpath "$(dirname "$0")")
+
+dotnet run --project "$SCRIPT_DIR/CodeGen" --update-nano-framework-dependencies