Update to fflate (#448)

* Update to fflate

* Update docs, bundler config

src/packer/pack.ts

@@ -1,4 +1,4 @@
-import { deflate } from 'pako/dist/pako_deflate';
+import { strFromU8, strToU8, zlibSync } from 'fflate';
 import { PackFn, MARK, eventWithTimeAndPacker } from './base';
 
 export const pack: PackFn = (event) => {
@@ -6,5 +6,5 @@ export const pack: PackFn = (event) => {
     ...event,
     v: MARK,
   };
-  return deflate(JSON.stringify(_e), { to: 'string' });
+  return strFromU8(zlibSync(strToU8(JSON.stringify(_e))), true);
 };