refactor!: organize directories and files (#268)

* refactor!: organize directory structure

* fix: avoid stack overflow err

* chore: swtch back to std/encoding for base64

* style: format source files

src/util/cdn.ts

@@ -0,0 +1,10 @@
+import { ImageFormats, ImageSize } from "../types/types.ts";
+
+export const formatImageURL = (
+  url: string,
+  size: ImageSize = 128,
+  format?: ImageFormats,
+) => {
+  return `${url}.${format ||
+    (url.includes("/a_") ? "gif" : "jpg")}?size=${size}`;
+};