Add .js file extension to import, to make importmap work out of the box

Author: Martin Heide

index.web.js

@@ -1,5 +1,8 @@
 // In pure ESM web bundles, you must call init() and wait for the promised result before you can
 // call any module methods. To make that as easy as possible, this module directly exposes the
 // init() promise result, and returns the methods at the end of the promise.
-import init, * as brotliWasm from "./pkg.web/brotli_wasm";
+// https://github.com/WICG/import-maps?tab=readme-ov-file#extension-less-imports
+// For usage with an importmap, it's convenient to add the ".js" extension here, because browsers
+// don't try to guess the file extension.
+import init, * as brotliWasm from "./pkg.web/brotli_wasm.js";
 export default init().then(() => brotliWasm);