remove stashboard

https://github.com/twilio/stashboard
project archived
ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/3166

README.md

@@ -453,7 +453,6 @@
 
 **Please visit [awesome-selfhosted/Status / Uptime Pages](https://github.com/awesome-selfhosted/awesome-selfhosted#status--uptime-pages)**
 
-* [Stashboard](http://www.stashboard.org) - Status page for cloud services and APIs.
 * [System Status Dashboard (SSD)](http://www.system-status-dashboard.com/) - Overview about an organization's infrastructure health status.
 * [vigil](https://github.com/valeriansaliou/vigil) -  Microservices Status Page. Monitors a distributed infrastructure and sends alerts to Slack. Written in Rust.
 * [Statping-ng](https://github.com/statping-ng/statping-ng) - Status page system written in Go (Active fork of statping).