Better onboarding experience

From a recent user study, we found that users could not discover the useful IDE features that come with Flutter plugin such as Outline or Inspector, while exploring Flutter for an hour.

I think we can provide better onboarding information early on so that they can make the most out of the tools, rather than waiting for them to discover the features sometime in the future.

There are multiple ways to do this:

1. Add a step in “[Test Drive](https://flutter.io/docs/get-started/test-drive?tab=androidstudio)” page that invites users to try out inspector and outline
2. Improve the [documentation on IntelliJ](https://flutter.io/docs/development/tools/android-studio) on flutter.io
- Add a short description about code formatting, inspector, outline in this page that links to a more detailed page
- Add more items under Tips and tricks > Cheat sheet

3. Give a quick tour of IDE features as the last step of installation, when a user installs Flutter plugin within IntelliJ

This issue is not urgent, but I will communicate with flutter/website as well to see if they have bandwidth for (1) and (2) and follow up on this issue.

Cc: @InMatrix @galeyang