design: Move to core subdirectory

These are generally useful pages for all users of Dovecot (not just
developers).

But this is a necessity for Pro as there are links to some of these pages that
otherwise break builds (e.g. to events page)

Author: slusarz

data/updates.js

@@ -23,6 +23,7 @@ export const updates = {
 	auth_server_common_secured: '2.4.0',
 	dcrypt_same_cipher_algo_added: '2.4.0',
 	dict_idle_timeout_added: '2.4.0',
+	dict_protocol_v4: '2.4.0',
 	dict_slow_warn_added: '2.4.0',
 	doveadm_ex_expired_code: '2.4.0',
 	doveadm_mailbox_commands_user: '2.4.0',