Discord has now moved to use X-Audit-Log-Reason as the preferred way for bots to provide audit log reasons for certain actions around guilds and channels. There are quite a lot of endpoints that support this.

Two ideas are:

1. Add an optional field for reason in the body of every HTTP endpoint, and move it into a HTTP header within restCall
2. Create some generic modifier function like restCall $ AuditLogReason "bad user" $ CreateGuildBan opts etc...

Certain endpoints will need to be updated if we already have an existing reason field from the JSON body. For example, CreateGuildBanOpts currently takes a reason field, and sends it to Discord, but it's not clear if Discord actually uses this since the field has now been removed from their docs.