move styles and js to the root directory

styles/components/_workspace_layout.scss

@@ -0,0 +1,26 @@
+.workspace-panel-container {
+  @include media($large-screen) {
+    @include grid-row;
+  }
+}
+
+.workspace-navigation {
+  @include panel-margin;
+
+  ul {
+    display: flex;
+    flex-wrap: wrap;
+    li {
+      flex-grow: 1;
+    }
+  }
+
+  @include media($large-screen) {
+    width: 20rem;
+    margin-right: $gap * 2;
+
+    ul {
+      display: block;
+    }
+  }
+}