Remove Pro prerequisite from Webhook tutorial

[Andre601]

The tutorial about hooking Uptime robot into Discord without third parties mentions that you need a Pro account on Uptimerobot as a Prerequisite, which is completely wrong.

Webhooks can be send without the requirement of a Pro account and the only different you would have is a lower delay in-between checks which iirc is not used while a monitor is down (UR will monitor more frequently while the monitor is down to give precise downtime measures afaik).

This should be updated to at least mentioning that it's optional.