Made the "Custom HTML Head Content" setting a highlighted code editor

resources/js/components/code-textarea.js

@@ -0,0 +1,16 @@
+/**
+ * A simple component to render a code editor within the textarea
+ * this exists upon.
+ * @extends {Component}
+ */
+class CodeTextarea {
+
+    async setup() {
+        const mode = this.$opts.mode;
+        const Code = await window.importVersioned('code');
+        Code.inlineEditor(this.$el, mode);
+    }
+
+}
+
+export default CodeTextarea;