Special Channel Access based on # of contributions

I want to have different channels on discord for different contributor levels. They are view-only unless you have a certain number of contributions, at which point you're granted a role that enables you to post in that tier

Not bountying because I don't know if it's possible and it's not important for the short term

- 1-10: `c-tier`
- 10-100: `b-tier`
- 100+: `a-tier`