Add missing word to compiling CSS exercise (#80)

exercises/01.styling/04.problem.compiling-css/README.mdx

@@ -57,7 +57,7 @@ Tailwind with PostCSS in
 [the Tailwind docs](https://tailwindcss.com/docs/using-with-preprocessors).
 
 <callout-danger>
-	Remix may not pick up on the new config files until you restart the dev.
+	Remix may not pick up on the new config files until you restart the dev server.
 	Simply click "Stop App" and then "Start App" again to restart the dev server.
 	That should work, but if it doesn't, stop the workshop app and restart it.
 </callout-danger>