Add MQTT autodiscovery docs

[Mirodin]

re PR: arendst/Tasmota#9267

Please add the new feature to the appropriate article in Tasmota documentation

I might have missed it but I could not find documentation for the payload other than in the previously mentioned issue.

[barbudor]

Tasmota docs are open source and are maintained by the community, people like YOU
If you can't help tasmota with code, you can help with improving the documentation.
Thanks in advance for your support.

[Mirodin]

I see I might have worded this incorrectly, I was not planing to sound demanding - sorry for that, I am not a native.

I am more than happy to help, is there like a template I can use? Also where should that go? I figure there is not enough to warrant a full separate "page"?

[barbudor]

Actually there is no dedicated page on Tasmota Discovery for now.
At least it may be good tell a little more on the Home Assistant page as this is where people would seek information.

My own idea would be:

• In the section "Tasmota Integration": state that this replace the obsolete HA MQTT Discovery (SetOption19 1)
• In the section on "MQTT Discovery REMOVED": state that this has been replaced by the new "Tasmota Integration" based on Tasmota Discovery.

You can edit and suggest change by clicking on the pencil button on the top right of the page.
That will help you create a fork of the doc repository into your own GitHub account where you will make the change.
Then submit your changes by creating a PR (pull request) to the original Tasmota/docs repository

This README provides some help and guidelines.
You mainly have to look what is about the markdown syntax and extensions that is used.

If you have any difficulties or questions, just follow on this thread.
The more we have people that can collaborate on docs, the better the doc is