docs: add support policy to FAQ

Author: xmatthias

docs/faq.md

@@ -297,6 +297,13 @@ Should you be asked to expose your exchange keys or send funds to some random wa
 
 Failing to follow these guidelines will not be responsibility of freqtrade.
 
+## Support policy
+
+We provide free support for Freqtrade on our [Discord server](https://discord.gg/p7nuUNVfP7) and via GitHub issues.
+We only support the most recent release (e.g. 2025.8) and the current development branch (e.g. 2025.9-dev).
+
+If you're on an older version, please follow the [upgrade instructions](updating.md) and see if your problem has already been addressed.
+
 ## "Freqtrade token"
 
 Freqtrade does not have a Crypto token offering.