Add VSCode

[jnywong]

Some lessons learned from this build:

• jupyter/base-notebook:python-3.12 does not come with git
• need to install ms-python.python for VSCode to work with Python
• code-server lives in /opt/conda/bin/code-server
• nodejs v18 already comes with the base image
• ReferenceError: crypto is not defined requires a higher version of nodejs, so I pinned code-server to a lower version using vscode-binder as an example 🎉