CrateRow: Show "Copy" button only when the row is hovered

Author: Turbo87

app/components/crate-row.hbs

@@ -10,7 +10,7 @@
         {{ @crate.name }}
       </LinkTo>
       <span local-class="version" data-test-version>v{{@crate.max_version}}</span>
-      <CrateTomlCopy @copyText='{{@crate.name}} = "{{@crate.max_version}}"' @inline={{true}} />
+      <CrateTomlCopy @copyText='{{@crate.name}} = "{{@crate.max_version}}"' @inline={{true}} local-class="copy-button" />
     </div>
     <div local-class="description" data-test-description>
       {{ truncate-text @crate.description }}

app/components/crate-row.module.css

@@ -21,6 +21,15 @@
     margin-left: 10px;
 }
 
+.copy-button {
+    opacity: 0;
+    transition: 50ms;
+
+    .crate-row:hover & {
+        opacity: 1;
+    }
+}
+
 .description {
     composes: small from '../styles/shared/typography.module.css';
     margin-top: 8px;