add notebook-support by default

[jonah-iden]

What it does

This adds the builtin extensions for notebook support by default to the plugins folder.

Currently this is kind of confusing for most users coming from vscode, that they have to install 2 additional extensions they might never have heard about (the butilin ipynb and builtin notebook renderers). Having the support available by default should make this far easier.

How to test

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• as a reviewer, I agree to behave in accordance with the review guidelines

[jfaltermeier]

Thanks!