Config.txt

I can’t find any document that specifies all the possible config.txt keywords, their possible values and meaning.

I want to configure console resolution and hot-plug, ethernet static IPV4 address, wifi credentials, etc.

If such document exists please let me know where I can find it.

This is not done in config.txt. There is a GUI at Settings → System → Network → (your adaptor) → IPv4

The rest is not specific to HA and you need to check the raspberry pi resource. https://www.raspberrypi.com/documentation/computers/config_txt.html