Nodejs.dev: Change default branch name from master -> main

[MylesBorins]

We are looking at making changes to repos in the org before making this change in nodejs/node.

Anyone have concerns with rolling this out on nodejs.dev?

I will personally roll everything out and ensure all automations continue to work as expected.

[benhalverson]

Hey @MylesBorins I have no concerns, if you can make it a smooth transition 👍

[MylesBorins]

I'll likely take a pass at this on Friday, so if anyone has objections please raise them before then.

The process will include retargeting all open PRs against the new main branch, renaming the master -> main. Folks working on the repo will need to update their local repos.