chore: flatten interface dirs #3959

Job	Run time
Build	3m 6s
Test example js-libp2p-example-browser-pubsub	2m 25s
Test example js-libp2p-example-chat	1m 23s
Test example js-libp2p-example-circuit-relay	1m 31s
Test example js-libp2p-example-connection-encryption	54s
Test example js-libp2p-example-custom-protocols	2m 32s
Test example js-libp2p-example-delegated-routing	1m 50s
Test example js-libp2p-example-discovery-mechanisms	2m 44s
Test example js-libp2p-example-peer-and-content-routing	1m 8s
Test example js-libp2p-example-pnet	1m 0s
Test example js-libp2p-example-protocol-and-stream-muxing	1m 3s
Test example js-libp2p-example-pubsub	1m 41s
Test example js-libp2p-example-transports	2m 58s
Test example js-libp2p-example-webrtc-private-to-private	2m 18s
	26m 33s

Provide feedback