feat: add comments and cleanup unused imports across codebase

static/q.ts

@@ -1,7 +1,16 @@
+/**
+ * querySelector on a container element, scoped to that element.
+ */
 export const q = <T extends Element>(container: HTMLElement, selector: string): T | null =>
   container.querySelector(selector) as T | null;
 
+/**
+ * querySelector on the document.
+ */
 export const qs = <T extends Element>(selector: string): T | null =>
   document.querySelector(selector) as T | null;
 
+/**
+ * Get a data attribute value from an element, defaults to empty string.
+ */
 export const dataset = (el: HTMLElement, key: string): string => el.dataset[key] ?? '';