Add init command for browser tests

[sheremet-va]

Clear and concise description of the problem

Currently, enabling browser mode is not a very straightforward process. As a user who just wants to try it, I need to:

• enable browser in the config
• run vitest, see @vitest/browser is not installed
• install @vitest/browser
• see webdriverio is not installed
• ask yourself what webdriverio is, install it
• run vitest, see I forgot the browser name
• add browser name to the config

Suggested solution

1. We need to improve documentation on how the browser mode works internally
2. Add vitest init-browser-mode (name TBD) command that asks what provider should be installed and what browser, then it scaffolds files to enable the browser mode integration:
   a. installs the @vitest/browser + provider package + adds @vitest/browser/providers/{name} to tsconfig

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[MatanBobi]

This one is extremely funny for me because I just bumped into every step mentioned 😅
At least in the meantime I think we should add installation page. I'd love to help with that if needed.

[sheremet-va]

This one is extremely funny for me because I just bumped into every step mentioned 😅 At least in the meantime I think we should add installation page. I'd love to help with that if needed.

The PR is welcome 😄

[MatanBobi]

Thanks @sheremet-va, I've created #5799 in the meanwhile to clarify installation and configuration steps :)