NIP-19: Add nrelay encoding and decoding

nip19.test.js

@@ -100,3 +100,12 @@ test('decode naddr from go-nostr with different TLV ordering', () => {
   expect(data.kind).toEqual(30023)
   expect(data.identifier).toEqual('banana')
 })
+
+test('encode and decode nrelay', () => {
+  let url = "wss://relay.nostr.example"
+  let nrelay = nip19.nrelayEncode(url)
+  expect(nrelay).toMatch(/nrelay1\w+/)
+  let {type, data} = nip19.decode(nrelay)
+  expect(type).toEqual('nrelay')
+  expect(data).toEqual(url)
+})