[Suggestion] Codex improvements

[ToasterPig]

After fiddling around with the codex, I only noticed the small question mark in the corner after trying to start the mod, reading the starting entries then giving up because none of them told me how I should start or what the mod does then coming back after doing something else. I feel like there should be an opening entry telling me how to use the codex or make it like the Thauminomicon where once you create/pick up x item from the codex it unlocks the next entry automatically instead of needing to do it manually.