add note about Raycast extension (closes #512)

README.md

@@ -145,6 +145,10 @@ Firefox:
 javascript:(function(){function notify(msg) {var sc = document.scrollingElement.scrollTop; var text = document.createElement('span');text.innerHTML=msg;var ts = text.style;ts.all = 'revert';ts.color = '#000';ts.fontFamily = 'Verdana, sans-serif';ts.fontSize = '15px';ts.backgroundColor = 'white';ts.padding = '15px';ts.border = '1px solid gainsboro';ts.boxShadow = '3px 3px 10px';ts.zIndex = '100';document.body.appendChild(text);ts.position = 'absolute'; ts.top = 50 + sc + 'px'; ts.left = (window.innerWidth / 2)-(text.offsetWidth / 2) + 'px'; setTimeout(function () { text.style.visibility = "hidden"; }, 1500);}xhr=new XMLHttpRequest();xhr.open("POST","https://metube.domain.com/add");xhr.send(JSON.stringify({"url":document.location.href,"quality":"best"}));xhr.onload=function() { if(xhr.status==200){notify("Sent to metube!")}else {notify("Send to metube failed. Check the javascript console for clues.")}}})();
 ```
 
+## Raycast extension
+
+[dotvhs](https://github.com/dotvhs) has created an [extension for Raycast](https://www.raycast.com/dot/metube) that allows adding videos to MeTube directly from Raycast.
+
 ## HTTPS support, and running behind a reverse proxy
 
 It's possible to configure MeTube to listen in HTTPS mode. `docker-compose` example: