Description

In order to speed up CI, we have to be able to run quibble locally. The first step is being able to build the documentation locally. Quibble is a python project and not everybody will have everything set up correctly. Adding a devcontainer.json will make it explicit what is needed to build the documentation. It will also make it trivial for anybody using vscode to get the required environment set up locally.

For more information, see parent task T418234: Update Quibble documentation.

Acceptance criteria

• .devcontainer/devcontainer.json is added to quibble