Fix README IRC connection instructions

[JoesnageL]

Fixes #37.

Summary

• Remove the stale README example for ssh -t irc@bbs.profullstack.com
• Replace the obsolete internal/irc mention with the supported native TLS/WebSocket IRC paths
• Tidy comments that still listed irc@ as a terminal takeover/session app route

Verification

• git diff --check
• Not run: go test ./... because Go is not installed in this environment