Now that we have a set of dark mode color tokens in Codex, we should update our documentation site to support color scheme switching.

We should do the following things to get this working:

• re-enable the built-in Vitepress color mode switcher
• Update the Vitepress theme to use the appropriate Codex dark mode tokens instead of any provided by the theme
• Ensure that our custom components (Wrapper, code snippets, etc) all support mode switching using the appropriate color tokens

If need be, we could handle this as a small epic with a couple of sub-tasks.