Add /firm exporthotm to save hotm presets

src/main/kotlin/events/SlotRenderEvents.kt

@@ -3,7 +3,10 @@
 package moe.nea.firmament.events
 
 import net.minecraft.client.gui.DrawContext
+import net.minecraft.client.texture.Sprite
 import net.minecraft.screen.slot.Slot
+import net.minecraft.util.Identifier
+import moe.nea.firmament.util.MC
 
 interface SlotRenderEvents {
     val context: DrawContext
@@ -12,6 +15,13 @@ interface SlotRenderEvents {
     val mouseY: Int
     val delta: Float
 
+	fun highlight(sprite: Sprite) {
+		context.drawSprite(
+			slot.x, slot.y, 0, 16, 16,
+			sprite
+		)
+	}
+
     data class Before(
         override val context: DrawContext, override val slot: Slot,
         override val mouseX: Int,