Fix excessive whitespace in v3 docs (#4062)

Author: johha

docs/v3/source/layouts/layout.erb

@@ -29,6 +29,7 @@ table_of_contents = extract_table_of_contents(html)
     <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible">
     <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
     <title><%= current_page.data.title || "API Documentation" %></title>
+    <%= stylesheet_link_tag "custom", :media => "screen" %>
     <%= favicon_tag 'favicon.ico' %>
 
     <%= stylesheet_link_tag :screen, media: :screen %>

docs/v3/source/stylesheets/custom.css

@@ -0,0 +1,5 @@
+
+/* Ensures that divs with the class 'highlight' don't take up the full width of the page preventing excessive whitespace */
+.highlight {
+    display: inline;
+}