Mailu

Adding a new Package

• This package is Open Source.
• The ansible role to install this package has been created.
• The documentation page for this package has been added.
• mkdocs.yml has been updated with a link to this package's documentation.
• The package has been added to group_vars/all under the # Enabled List, enabled_services:, and services: sections.
• The package has been added to README.md.
• The package has been added to CHANGELOG.md for the version currently in development.
• The package has been added to roles/homelabos_config/templates/config.yml.j2 under the # Services List section.
• This ansible template uses the password module for security.
• This Merge Request follows the contributing guidelines.

Closes #166 (closed)