stonecutter: setup project for multiversion support

- Switch to Stonecutter build system
- Migrate mappings to Mojmap

src/main/resources/META-INF/neoforge.mods.toml

@@ -0,0 +1,37 @@
+modLoader = "javafml"
+loaderVersion = "[2,)"
+#issueTrackerURL = ""
+license = "MIT License"
+
+[[mods]]
+modId = "${id}"
+version = "${version}"
+displayName = "Puzzle"
+logoFile = "puzzle.png"
+authors = "PuzzleMC, Motschen"
+description = '''
+Unites optifine replacement mods in a clean & vanilla-style gui
+'''
+
+[[mixins]]
+config = "puzzle-gui.mixins.json"
+[[mixins]]
+config = "puzzle-models.mixins.json"
+[[mixins]]
+config = "puzzle-splashscreen.mixins.json"
+[[mixins]]
+config = "puzzle-splashscreen_neoforge.mixins.json"
+
+[[dependencies.puzzle]]
+modId = "neoforge"
+mandatory = true
+versionRange = "[21.0,)"
+ordering = "NONE"
+side = "CLIENT"
+
+[[dependencies.puzzle]]
+modId = "minecraft"
+mandatory = true
+versionRange = "[1.21,)"
+ordering = "NONE"
+side = "CLIENT"