v1.4.0 release

This release added support for decoding/encoding Nostr's NIP-19 entities.

It is possible to decode/encode NIP-19 entities as follows:

# Decode bare entity
bech32 = 'npub10elfcs4fr0l0r8af98jlmgdh9c8tcxjvz9qkw038js35mp4dma8qzvjptg'
entity = Bech32::Nostr::NIP19.parse(bech32)
entity.hrp
=> 'npub'
entity.data
=> '7e7e9c42a91bfef19fa929e5fda1b72e0ebc1a4c1141673e2794234d86addf4e'

# Decode tlv entity
bech32 = 'nprofile1qqsrhuxx8l9ex335q7he0f09aej04zpazpl0ne2cgukyawd24mayt8gpp4mhxue69uhhytnc9e3k7mgpz4mhxue69uhkg6nzv9ejuumpv34kytnrdaksjlyr9p'
entity = Bech32::Nostr::NIP19.parse(bech32)
entity.hrp
=> 'nprofile'
entity.entries[0].value
=> '3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d'
entity.entries[1].value
=> 'wss://r.x.com'

# Encode bare entity
entity = Bech32::Nostr::BareEntity.new('npub', '7e7e9c42a91bfef19fa929e5fda1b72e0ebc1a4c1141673e2794234d86addf4e')
entity.encode
=> 'npub10elfcs4fr0l0r8af98jlmgdh9c8tcxjvz9qkw038js35mp4dma8qzvjptg'

# Encode tlv entity
entry_relay = Bech32::Nostr::TLVEntry.new(Bech32::Nostr::TLVEntity::TYPE_RELAY, 'wss://relay.nostr.example')
entry_author = Bech32::Nostr::TLVEntry.new(Bech32::Nostr::TLVEntity::TYPE_AUTHOR, '97c70a44366a6535c145b333f973ea86dfdc2d7a99da618c40c64705ad98e322')
entity = Bech32::Nostr::TLVEntity.new(Bech32::Nostr::NIP19::HRP_EVENT, [entry_relay, entry_author])
entity.encode
=> 'nevent1qyvhwumn8ghj7un9d3shjtnwdaehgu3wv4uxzmtsd3jsygyhcu9ygdn2v56uz3dnx0uh865xmlwz675emfsccsxxguz6mx8rygstv78u'