The sentiment "am shutting this site down boring" suggests several common digital era themes that could form the basis of a feature:
Best-in-class for real-time document editing and large ecosystem support. Lessons from Recent Shutdowns ajb nippyfile am shutting this site down boring
Cheers, [Your Name/Admin]
Here is a draft you can use to announce the shutdown. It balances a bit of "I'm over it" with a clean break for the users. The sentiment "am shutting this site down boring"
If you want, I can:
See you on the other side.