Update old wiki link

[Piinks]

Part of flutter/flutter#145009

Pre-launch Checklist

• I read the Effective Dart: Style recently, and have followed its advice.
• I signed the CLA.
• I updated/added relevant documentation (doc comments with ///).
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-devrel channel on Discord.

[parlough]

Thanks!

Do consider linking to main instead since it contains the mirrored content and will hopefully be the default in the future, while avoiding the need to update it again.

[Piinks]

Thanks for the review!

Do consider linking to main instead since it contains the mirrored content and will hopefully be the default in the future, while avoiding the need to update it again.

I wanted to, but in the past it has confused folks that want to contribute. They'll send PRs to the main branch instead of master, where we are still anchored. However, this is a bit duplicitous since flutter/flutter's analyzer script checks against links containing master. 🙃

I do hope we switch fully over to main. I would really prefer it.