Update README.md

README.md

@@ -19,6 +19,18 @@ You are to run a range of security tests and scans along with a white/grey/black
 
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+## Sandbox Environments
+
+Sandboxing creates a safe place to install or execute a program, particularly a suspicious one, without exposing the rest of your system or network. It keeps the code contained in a test environment, so it can't change the state of the host machine, operating system or networked resources. Simple-to-use sandbox environments for Python Flask include:
+
+- [GitHub Codespaces](https://github.com/features/codespaces)
+- [CodeSandbox.io](https://codesandbox.io/)
+- [Docker Container](https://code.visualstudio.com/docs/devcontainers/containers)
+
+__The Unsecure PWA includes a devcontainer.json to auto-configure all the above sandboxes.__
+
+---
+
 > [!Tip]
 > ## Teaching advice:
 >