Hassbian: Added new alias halog

[ludeeus]

Description:

Added new alias for the pi user:

alias halog='sudo journalctl -f -u home-assistant@homeassistant.service'

Also added docs for this well hidden feature :)

Related issue (if applicable): Fixes #N/A

Checklist (Required):

• The code change is tested and works locally.
• The code is compliant with Contributing guidelines

If pertinent:

• Script has validation check of the job.
• Created/Updated documentation at /docs