Remove dead link

ddevault's capsule was spun down months ago with no indication that he plans to restore it

README.md

@@ -197,7 +197,6 @@ Repo mirrors:
 
 ## Services
 - __gemini://warmedal.se/~antenna/__ - Geminispace aggregator
-- __gemini://drewdevault.com/cgi-bin/man.sh__ - look up a POSIX man page.
 - __gemini://flounder.online__ ([https version](https://flounder.online/)) - host small Gemini web pages over https and Gemini ([repo](https://github.com/alexwennerberg/flounder)).
 - __gemini://geminispace.info__ - public search provider for Gemini ([repo](https://src.clttr.info/rwa/geminispace.info)).
 - __gemini://geddit.glv.one__ - interactive link service (with comments).