Document how to use `.devcontainer`

[alamb]

• Part of [Epic] Better / Improved Documentation, Tutorials and Examples #7013

@rluvaton added .devcontainer in #13520

I think we should document that this exists / how to use dev containers in the documentation. Perhaps at

https://datafusion.apache.org/contributor-guide/getting_started.html#getting-started

Originally posted by @alamb in #13520 (comment)

Perhaps we can add a note saying DataFusion supports dev containers, and refer to relevant files / documetnation. For example

https://docs.github.com/en/codespaces/setting-up-your-project-for-codespaces/adding-a-dev-container-configuration/introduction-to-dev-containers

[Omega359]

Might want to use my personal one as a template - https://github.com/Omega359/arrow-datafusion/blob/feature/devcontainer/.devcontainer/README.md

[alamb]

I was just playing around with this on github codespaces -- it is mind blowing that the full IDE /testing can be done in the browser too (basically for free):

[Omega359]

Wow, that is crazy. I had no idea it could do that.