Add editor structure outline to the developer guide on the website

website/static/js/developer-guide-editor-structure.js

@@ -0,0 +1,17 @@
+document.addEventListener("DOMContentLoaded", () => {
+	document.querySelectorAll(".tree-node").forEach((toggle) => {
+		toggle.addEventListener("click", (event) => {
+			// Prevent link click from also toggling parent
+			if (event.target.tagName === "A") return;
+			
+			const nestedList = toggle.parentElement.querySelector(".nested");
+			if (nestedList) {
+				toggle.classList.toggle("expanded");
+				nestedList.classList.toggle("active");
+			}
+		});
+	});
+
+	// Expand the first level by default
+	document.querySelector(".structure-outline > ul > li > .tree-node")?.click();
+});