Add avatar icon when thread closed

[Anubhav1603]

Is your feature request related to a problem? Please describe.
when thread get closed it dont show the details of mod who closed the thread,so its hard to predict mod has replied or modmail closed the thread on its own

Describe the solution you'd like
When thread gets closed by mod then bot should add mod avatar and little info thread has been closed by modname then text

Describe alternatives you've considered
Currently didnt able to think of any.

Who will this benefit
the author who writes to modmail

Additional context
Add any other context or screenshots about the feature request here.

[fourjr]

Hey, the name of mod is shown in the footer

[fourjr]

We will add the footer icon though