With this method you will not get this achievement for free, you still need to collect all the books.
I found all the books during normal gameplay without too much trouble.









So how to get this achievement?

1. Download https://drive.google.com/file/d/1jchZByRP8blYwtj7jK1TtnxblPwcmVYj/view?usp=sharing

2. Paste downloaded Assembly-CSharp.dll file to:
...SteamLibrary\steamapps\common\Sheltered 2\Sheltered2_Data\Managed\
and replace file in the destination(you can make a backup)

3. Run the game

4. Get all the books. If you already have all books in shelter inventory then moving some books to junk pile and putting them back to shelter inventory should trigger check function.
The game always checks for this achievement every time you add books to the shelter inventory(without or with this fix)

5. After obtaining this achievement restore original Assembly-CSharp.dll either from backup or by verifying files integrity



Why achievement didn't work?
I didn't add anything new to this file. The game checked if you have all books in an incorrect place so I copied checking to the right place.