Add Replugged support (and remove Powercord)

Powercord is kill, Replugged now uses asars for themes. `updater` in `manifest.json` assumes that you'd want to have this published on the store (by submitting this and future updates in #theme-dev on the Replugged server) - if not, then it can be changed to update from GitHub instead: ```json "updater": { "type": "github", "id": "DiscordStyles/RadialStatus" } ```