Hi namgo, welcome! Yes, I didn't have time yet to write specifications for all components, but you should not need them unless you want to go low level and write your game in assembler. The idea of the specs is to fully define how the console works so that anyone can create their own emulators. But for creating games, I believe it should be enough with the guides and tutorials, as well as the examples in GitHub.
Still if you are in doubt about something I will try to answer as soon as possible ;)
I don't have a dedicated Discord server, but I do have a channel in the Fantasy Consoles 2.0 Discord server. I'm still new there so I'm not sure how invitations work but I will ask ProHiScore about this so that you can join us there.