update tsconfig

tsconfig.json

@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
-    "target": "es5",
+    "lib": ["es2020"],
+    "target": "es2020",
     "module": "commonjs",
     "outDir": "./lib",
     "declaration": true,
@@ -8,7 +9,6 @@
     "strict": true,
     "noUnusedLocals": true,
     "esModuleInterop": true,
-    "lib": ["es6"]
   },
   "include": ["./src/**/*", "tests/streams.test.ts"]
 }