Add expansion panels styling

src/lib/src/main/resources/swagger/index.css

@@ -94,3 +94,26 @@ body {
   position: absolute;
   top: -.2em;
 }
+
+details {
+  cursor: pointer;
+  box-shadow: 0 3px 1px -2px #0003, 0 2px 2px #00000024, 0 1px 5px #0000001f;
+}
+
+details:hover {
+  background-color: #f3f3f3;
+}
+
+details[open] {
+  background-color: initial;
+  padding: 0 1.5em 1.5em 1.5em;
+}
+
+summary {
+  font-weight: bold;
+  padding: 1.5em;
+}
+
+details[open] > summary {
+  margin-left: -1.5em;
+}