feat: improve helia 101 example

[2color]

What

• 101: adapt example to the changes introduced by fix!: require path in addFile call ipfs/helia#754
• 101: add more examples on how to use UnixFS in 101, including nuances around bytes/files/directories
• 201: change to focus on a single node and different block stores
• 201: use helia/http since we don't care about providing
• 401: add new example showing gc, providing, and pinning
• README: update for the example. Move code specific docs inline rather than README.

Additions for a followup

• Configuring block brokers & routers
• CAR files
• MFS

TODO

• Fix failing test (failing because of Error when two js-libp2p nodes on the same machine listen on '/ip4/0.0.0.0/udp/0/webrtc-direct' libp2p/js-libp2p#3049) no longer relevant since we only create one node and
• Update @helia/unixfs to 5 once chore: release main ipfs/helia#766 is merged
• Update the README

[2color]

@achingbrain When running the new 401 example my node hangs indefinitely when calling provide() for a CID:

helia-examples/examples/helia-101/401-providing.js

Lines 57 to 77 in aa5b910

	cid = await fs.addFile({
	content: encoder.encode(text),
	path: './hello-world.txt',
	})
	console.log('Added file again:', cid.toString())
	// Pin the block and add some metadata
	for await (const pinnedCid of helia.pins.add(cid, {
	metadata: {
	added: new Date().toISOString(),
	addedBy: '401-providing example',
	},
	})) {
	console.log('Pinned CID to prevent garbage collection:', pinnedCid.toString())
	}
	const pin = await helia.pins.get(cid)
	console.log('Pin:', pin)
	// Provide the block to the DHT so that other nodes can find and retrieve it
	await helia.routing.provide(cid)

• Helia is started with the defaults
• To debug I ran DEBUG="libp2p:upnp-nat*,libp2p:auto-nat*" node 401-providing.js
• I'm doing this on a network with upnp enabled. AutoTLS works with Kubo. The router is a Ubiquiti one.
• The full log
  • What's interesting is that in the logs it prints multiple times: libp2p:upnp-nat gateway search finished, found 0 gateways +5s
  • However, it seems that it succeeds getting a port mapping, given all the log lines libp2p:auto-nat /ip4/87.x.x155/udp/61391 success 0 failure 6 +11s where 87.x.x.155 is in fact the correct public IP.

I'm not too familiar with the @libp2p/upnp-nat, but maybe you have some insights?

Update 19.3

• I ran the same example as above on a different network (my home)
• helia outputs multiple times: libp2p:upnp-nat gateway search finished, found 0 gateways +5s
• It seems to be able to create a port mapping, but for some reason AutoNATfails
• Logs

[achingbrain]

LGTM, a couple of comments inline.