added dev container

Author: JetterMcTedder

README.md

@@ -4,6 +4,9 @@
 
 Can't install VS Code? Or the drivers? Or just want to test drive these examples? No problem! Create a codespace on this repository with everything you need pre-installed!
 
+[![Open in GitHub Codespaces](https://github.com/codespaces/badge.svg)](https://github.com/codespaces?codespace[ref]=main&current_branch=main&event_target=REPO_PAGE&repo=660781253).
+
+
 #### Driver examples include:
 
 * [C#](./examples/sql/drivers/csharp-driver-example.md)