Describe the discord role management

[marchermans]

This PR provides an overview of how our Discord roles are managed.
Its primary job is to formalize the way roles are distributed and to whom.
Additionally, it defines how team members can get high privileged roles that should not be used in day to day management work.

Old Roles -> New Roles

Added Roles:

• PIM Bot
• All Vanity Roles

Changed Roles:

• Discord Admin -> Server Manager
• sudo -> Role Manager + Channel Manager
• Moderator -> Moderators
• Moderators -> Moderator
• Maintainer -> Maintainers
• Provisional Moderator + Provisional Maintainer -> Probation
• Foundation Member -> Foundation Team
• Trickster -> Bot Team
• Team Member -> NeoForged Team
• Crafters -> Mojang Team

Removed Roles:

• crown hider
• Various vanity roles (Moderation Lead, 1.8.9 dev, vice-cpw, moderator but ..., maintainer but ...)
• Moderaintainer
• NeoForm-ers
• Helper
• Former Member
• Docs Lead
• Rendering Team
• "Secret" Gradle
• Supervisor of Elections
• Observer
• Certified Old:tm:
• Space Nerd
• Threadusted

Potential roles to (re-)add:

Helper: This role would simply be an indicator and collection of knowledgeable people that can help out with technical problems the community has.

[IchHabeHunger54]

Changes recorded in the internal channel so far:

• Remove RetroGradle role, the project is dead for the foreseeable future
• Move Automation directly below NeoForged Team, to be able to properly moderate users

[sciwhiz12]

Some of my thoughts on this. Not all of them though, since I want to dispose of the more overarching thoughts before I dive into details.

[IchHabeHunger54]

Typos, grammar, and some minimal details.