feat: Cron implementation

[jonas-martinez]

Linked to https://github.com/lenra-io/lenra_cli/issues/75

Checklist

• [ ] I didn't over-scope my PR
• [ ] My PR title matches the commit convention
• [ ] I did not include breaking changes
• [ ] I included unit tests that cover my changes
• [ ] I added/updated the documentation about my changes
• [ ] I made my own code-review before requesting one

Description of the changes

Technical highlight/advice

[shiipou]

:tada: This PR is included in version 1.0.0-beta.81 :tada:

The release is available on:

• GitHub release
• v1.0.0-beta.81

Your semantic-release bot :package::rocket:

[shiipou]

:tada: This PR is included in version 1.0.0-alpha.1 :tada:

The release is available on:

• GitHub release
• v1.0.0-alpha.1

Your semantic-release bot :package::rocket: