Enemy almanac is already planned. (well, it was because right now it’s 4 years old and IA changes plans way too often so I’m not sure if it’s still in the to-do list since we don’t have any way of checking it through some roadmap).
Weapon almanac seems kinda too much given that there’s only 15(?) weapons, but I feel like it could work. Descriptions are lame, visuals are the king. It could also show you how certain power levels look. And you could complete it by using the weapon on certain power level. That would be a little fun objective to do.
Certainly the best almanac I ever seen in a vanilla game was in Terraria. Every single of them has name, filters, drops, visual, stats, biome, description and kill count. I could make a topic for overall CIU almanac but it’s planned so I’ll wait with suggestions when it gets added.