Replace dead Tydom2MQTT link in MQTT integration docs

### Feedback

The current link to Tydom2MQTT points to a retired GitHub Pages address and returns 404.

Update the Markdown so it resolves to the project’s new URL:
+[Tydom2MQTT](https://tydom2mqtt.github.io/tydom2mqtt/)

### URL

https://www.home-assistant.io/integrations/mqtt/#support-by-third-party-tools

### Version

2025.5.3

### Additional information

_No response_