Added Category.yml. Starting from this version, you can customize the classification and add more buttons to the classification GUI.
Added ItemCollection.yml and command /ca admin itemcollection, you can add an item containing a special NBT here, and use it in Category.yml (the next version will be extended to be used in blacklists and command /ca buy).
Fixed Bugs:
Fixed an click block's error when running on 1.13.x server.
Fixed an issue where items in the item list GUI could be taken away in 1.13.x server.
Fixed some minor bugs.
Updated configuration files. Fixed a bug where some placeholders in the default configuration file could not be used.
Plans for new features to be added in future releases:
Custom blacklist, you can prohibit items containing special attributes from being put on the market.
Json information support, so that some items sent to the public screen chat can display the properties of the item by moving the mouse to the cursor.
If you have more questions, or if you find a bug, please let me know in a private chat!