[dev] navbar toggle button (for mobile mode)

Author: Serhii Pylypchuk

src/css/custom.css

@@ -132,7 +132,7 @@ table {
 
 @media (max-width: 996px) {
   .navbar__toggle {
-      display: none;
+      display: block;
   }
   .menu--responsive .menu__button {
       border-radius: 100px;