Add item rarity backgrounds

src/main/kotlin/moe/nea/firmament/events/HotbarItemRenderEvent.kt

@@ -0,0 +1,20 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Linnea Gräf <nea@nea.moe>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package moe.nea.firmament.events
+
+import net.minecraft.client.gui.DrawContext
+import net.minecraft.item.ItemStack
+
+data class HotbarItemRenderEvent(
+    val item: ItemStack,
+    val context: DrawContext,
+    val x: Int,
+    val y: Int,
+    val tickDelta: Float,
+) : FirmamentEvent() {
+    companion object : FirmamentEventBus<HotbarItemRenderEvent>()
+}