Request: add stop_rtttl service

[Jaccer86]

First, thank you for this great project!

Would it be possible to add the stop_rtttl service to the original tagreader.yaml?

It allows you to stop a sound that is currently playing. This is really useful, for example, if you're playing a 'leaving home' or 'coming home' sound and you want to stop it once the alarm is (dis)armed.

api:
- service: stop_rtttl
then:
- rtttl.stop

[Jaccer86]

Resolved by adding the service manually to the yaml.