Compile JXL encoder

codecs/jxl_enc/jxl_enc.d.ts

@@ -0,0 +1,9 @@
+// import { EncodeOptions } from '../../src/codecs/avif/encoder-meta';
+
+interface JXLModule extends EmscriptenWasm.Module {
+  encode(data: BufferSource, width: number, height: number): Uint8Array;
+  free_result(): void;
+}
+
+
+export default function(opts: EmscriptenWasm.ModuleOpts): JXLModule;