ResourceModLoader is a module that allows loading non-executable Mods (Resource Mod), but can also be used as a library for modules written in Java.
In JE 1.13, data packs were added to Minecraft. Prior to this, the resource packs already had some data pack functions, such as using JSON to define a large number of recipes in more recipes, and mod authors could also use JSON to define their advancements. However, the data package functions of these resource packages can only be used in mods and cannot be applied to real resource packs.
This module reads the .zip and .jar file or directories containing the rml.info file in mods/, packages it as a mod and runs it.
For details, please view the brief official documentation.
Define recipes using JSON;
Define advancements using JSON.
Use JSON to define OreDic.
Load mcfunction.
Define the loot table using JSON.
Configuration value override.
Configuration values re-default.
Remap missing registry.
Define villagers.
Add splash texts.
Load the KubeJS script.
Load CrT script.

"More formulas" without mod structure are loaded by fml
ResourceModLoader is not a ModLoader and cannot load Mods instead of ModLoader.
The data does not have the overwriting function, only the <domain> that is the same as <modid> has the data packet function.
More information, see official document : https://ecdcaeb.github.io/ResourceModLoader/