Add configured compat

[no changelog]

src/main/kotlin/gui/config/BuiltInConfigScreenProvider.kt

@@ -0,0 +1,14 @@
+package moe.nea.firmament.gui.config
+
+import com.google.auto.service.AutoService
+import net.minecraft.client.gui.screen.Screen
+
+@AutoService(FirmamentConfigScreenProvider::class)
+class BuiltInConfigScreenProvider : FirmamentConfigScreenProvider {
+    override val key: String
+        get() = "builtin"
+
+    override fun open(parent: Screen?): Screen {
+        return AllConfigsGui.makeBuiltInScreen(parent)
+    }
+}