fix import in the example of README.md

Author: vogdb

README.md

@@ -40,7 +40,7 @@
 ```js
 import { TCP } from '@libp2p/tcp'
 import { Multiaddr } from '@multiformats/multiaddr'
-import pipe from 'it-pipe'
+import {pipe} from 'it-pipe'
 import all from 'it-all'
 
 // A simple upgrader that just returns the MultiaddrConnection