Evaluate what it would take to add IDX to a list of editors someone can use for Flutter

[sethladd]

What information needs to be added?

IDX has pretty good support for Flutter. We should evaluate what it would take for us to incorporate IDX into various docs, either in Editor enumerations, or in actual developer journeys.

Where should this new content appear?

Presumably, where we talk about editor support, and where we have "getting started" flows.

I would like to fix this problem.

• [ ] I will try and fix this problem on docs.flutter.dev.

[sethladd]

cc @jtmcdole

[jtmcdole]

It would be great if:

1. The user doesn't have to jump through multiple dialogs
2. The user doesn't have to enable third party cookies

[neiljaywarner]

It feels like IDX has gotten better in the last year, and since dartpad.dev lets you open in idx...