Minor fixes to Heading component; correct imports and default props.

client/src/components/Common/Heading.vue

@@ -1,4 +1,6 @@
 <script setup lang="ts">
+import { library } from "@fortawesome/fontawesome-svg-core";
+import { faAngleDoubleDown, faAngleDoubleUp } from "@fortawesome/free-solid-svg-icons";
 import { FontAwesomeIcon } from "@fortawesome/vue-fontawesome";
 import { computed } from "vue";
 
@@ -17,14 +19,18 @@ interface Props {
     collapse?: "open" | "closed" | "none";
 }
 
+library.add(faAngleDoubleDown, faAngleDoubleUp);
+
 const props = withDefaults(defineProps<Props>(), {
     collapse: "none",
+    icon: "",
+    size: "lg",
 });
 
 defineEmits(["click"]);
 
 const sizeClass = computed(() => {
-    return `h-${props.size ?? "lg"}`;
+    return `h-${props.size}`;
 });
 
 const collapsible = computed(() => {