This introduces the `dovecot_imap_capability` variable to allow customization of advertised IMAP capabilities.
- Add `dovecot_imap_capability` to `defaults/main.yml` (defaulting to empty).
- Update `templates/dovecot.conf.j2` to conditionally include the `protocol imap` block if the capability string is provided.
- This enables operators to add or remove specific IMAP extensions (e.g., disabling `LITERAL+` or `NOTIFY`) for client compatibility.
Introduces functionality to install and configure Dovecot alongside Postfix to provide IMAP/POP3 services.
Changes include:
- Added tasks to install Dovecot packages (core, imapd, pop3d, lmtpd).
- Added templates for main configuration and conf.d files (auth, master, ssl, mail).
- Defined default variables for protocols, SSL settings, and Maildir location.
- Enabled Postfix SASL and LMTP integration options.
- Added a handler to restart the Dovecot service.
- Updated README.md with the new configuration variables and usage instructions.
