This data pack transforms certain items placed in item frames into other items, after a configurable amount of time. By default the data pack converts raw meats (beef, chicken, mutton, porkchop, & rabbit) into rotten flesh, and potato into poisonous potato, but these recipes are provided mostly as examples. You can add your own recipes to the data pack, check the Adding Your Own Recipes section below.
By default item transformations take approximately 1 minute. If you'd like to change that, you can find the configuration file at "data\out_to_dry\functions\config.mcfunction" within the zip file of the data pack.
More information about data packs and how to use them can be found on the official Minecraft Wiki.
Adding Your Own Recipes
To add your own recipe, first copy one of the example recipe files from the data pack, and give it a new file name (make sure the file extension is still ".mcfunction"). Example recipes are included in the data pack, and can be found at "data\out_to_dry\functions\recipes" inside the zip file of the data pack.
Open your new recipe file and have a look. There are a few strings that you need to replace to make your new recipe. The first of these are instances of the ingredient (if you copied the poisonous_potato.mcfunction, this would be instances of "minecraft:potato"); these need to be changed out for the item name of the item you want to use as an ingredient. The second of these are instances of the resulting item (again, if you copied the poisonous potato recipe, this would be instances of "minecraft:poisonous_potato"); these need to be changed to the item name of the item you want the ingredient to be transformed into.
Once you've made a new recipe, there's one last change you need to make to the data pack. Open the "recipes.json" file located at "data\out_to_dry\tags\functions" within the data pack zip. You'll need to add a new entry to the "values" list in this file, specifying the name of the function you've created. This will be much like the other entries already in this list, but if you need some help on function naming conventions, I recommend reading the Functions page of the Official Minecraft Wiki. It may also be helpful for you to read the Tags page of the Official Minecraft Wiki, as the "recipes.json" file is a Tag file, and follows the same formatting requirements.
Recipes can be removed from the data pack in basically the inverse method of adding them. First, you need to remove the recipe's function listed in the "recipes.json" file located at "data\out_to_dry\tags\functions" within the data pack zip.
Without the entry in the "recipes.json", the recipe won't function, but if you want to remove it entirely, you can also find its function file within the "data\out_to_dry\functions\recipes" folder of the data pack zip, and remove its ".mcfunction" file from here too. Now the recipe is well and truly gone.