Make regex for domain lookup have optional transform group (#60)

Co-authored-by: Matt Kane <m@mk.gg>

src/transformers/cloudflare.ts

@@ -7,7 +7,7 @@ import {
 import { toUrl } from "../utils.ts";
 
 const cloudflareRegex =
-  /https?:\/\/(?<host>[^\/]+)\/cdn-cgi\/image\/(?<transformations>[^\/]+)\/(?<path>.*)$/g;
+  /https?:\/\/(?<host>[^\/]+)\/cdn-cgi\/image\/(?<transformations>[^\/]+)?\/(?<path>.*)$/g;
 
 const parseTransforms = (transformations: string) =>
   Object.fromEntries(transformations.split(",").map((t) => t.split("=")));