* 🐛 fix(server.go): validate IP address before starting server
✨ feat(server.go): add support for IPv6 addresses
* ✨ feat(cli): add support for IPv6 addresses in the `--listen` flag
* 🐛 fix(server.go): add nolint comment to ignore magic number warning in ipv6 check
* 🐛 fix(server.go): use fmt.Sprintf to format IP and port instead of strconv.Itoa and string concatenation
* 🎨 style(CHANGELOG.md): add UNRELEASED section
🔧 chore(notfound/handler.go): refactor to use core.RespondWithErrorPage
🔧 chore(http/server.go): pass config, templatePicker, renderer and options to notfoundHandler
🔧 chore(hurl/404.hurl): update test to expect HTML response instead of plain text
* 📝 docs(CHANGELOG.md): fix typo in changed section
* 🔥 chore(CHANGELOG.md): release version 2.22.0
🔥 chore(flags.go): remove unused code for serve command
