I accidentally forgot to push the recent changes, so all the stuff about the recipes is missing from github. Just fixed that. The JSON is located in the data/magic_overhaul/recipes folder and looks like this:
{
"type": "magic_overhaul:rune_inscribing",
"base": {
"item": "minecraft:stone"
},
"template": {
"item": "magic_overhaul:rune_template_acnar"
},
"output": {
"count": 1,
"item": "magic_overhaul:rune_acnar"
}
}