Use Cron+ and Home Assistant nodes

[shbatm]

Thanks for pulling this together! I finally gave up on the native Home Assistant integration and implemented this.

I made a few tweaks to simplify so I wanted to share it back in case you wanted to include:

1. Use Cron+ nodes to simplify the timing logic to 1 node instead of 3.
2. Use Home Assistant Websocket (and HACS Add-on) to add a native Home Assistant sensor with extra attributes and device class instead of going through MQTT.

No worries if you don't want to use it, just thought I'd share.

[stmrocket]

Thanks for the contribution! I'm glad you are finding this project useful. I'm always for simplified code so this is great.

I'll load up the changes and give it a try.

[stmrocket]

I now have the updated version running on my production system with no issues. I'll be moving most of my other projects to Cron+ and Home Assistant nodes as well after seeing how this all works.

@shbatm as we are no longer using MQTT, would you mind removing the references to it in the updated readme so it full reflects the new setup? Otherwise, I believe this is ready to merge.

[shbatm]

@stmrocket Glad you liked it. Sorry I got distracted this past month, updated the README as requested.

[stmrocket]

These features have been added in #15