add radius to companion badge

Author: pikinier20

scaladoc/resources/dotty_res/styles/theme/layout/content.css

@@ -236,6 +236,7 @@
   color: var(--text-primary);
   padding: 16px;
   background-color: var(--indigo3);
+  border-radius: 4px;
 }
 
 .companion-badge .micon {