fixes version switcher height

The panel expands to a max-height of 600, and shrinks to 100vh - 100px on browsers with height smaller than 600px.

docs/assets/style.css

@@ -540,6 +540,7 @@ ul.fas li .fa-large:before, ul.fas li .fa-large:before {
   bottom: 20px;
   display: block;
   left: auto;
+  height: calc(100vh - 100px);
   max-height: 600px;
   max-width: 300px;
   overflow: hidden;