Improve governance (second round)

[UlisesGascon]

Some pending tasks from previous round (#9):

• Automating the ## Style Guide with Prettier/equivalent
• Renaming master to main
• Remove squash commits suggestion
• Updating the #team on the yeoman/yeoman repo
• Implement GitHub issue forms and keeping a general catch-all issue template as a fallback. References: https://github.com/JoshuaKGoldberg/create-typescript-app/issues/new/choose and https://github.com/mochajs/mocha/issues/new/choose