Add footer link hover interaction

src/styles/components/_footer.scss

@@ -17,11 +17,30 @@
   }
 
   &__link {
+    position: relative;
     display: block;
     padding: 10px;
     font-weight: 700;
     color: inherit;
     text-decoration: none;
+
+    &::before {
+      position: absolute;
+      bottom: 6px;
+      left: 10px;
+      display: block;
+      width: calc(100% - 20px);
+      height: 2px;
+      background: $color-black;
+      content: '';
+      transform: scaleX(0);
+      transform-origin: left center;
+      transition: transform .5s $ease-out-quart;
+    }
+
+    &:hover::before {
+      transform: scaleX(1);
+    }
   }
 
   &__attribution {