Shorten "documentation" to "docs"

[#54897114]

_layouts/default.html

@@ -31,7 +31,7 @@ spring_site_url: http://sagan.cfapps.io
         </div>
         <ul class="nav pull-right">
           <li class="navbar-link">
-            <a href="{{page.spring_site_url}}/documentation">Documentation</a>
+            <a href="{{page.spring_site_url}}/docs">Docs</a>
           </li>
           <li class="navbar-link">
             <a href="{{page.spring_site_url}}/guides">Guides</a>

css/main.css.css

@@ -684,14 +684,14 @@ input.floating-input:focus {
   font-size: 14px;
   line-height: 19px;
 }
-.item--dropdown .item--body .item--body--version .documentation-link {
+.item--dropdown .item--body .item--body--version .docs-link {
   display: inline-block;
   color: #6db33f;
 }
-.item--dropdown .item--body .item--body--version .documentation-link:hover {
+.item--dropdown .item--body .item--body--version .docs-link:hover {
   color: #7ac04c;
 }
-.item--dropdown .item--body .item--body--version .documentation-link.reference-link {
+.item--dropdown .item--body .item--body--version .docs-link.reference-link {
   border-right: 1px solid #4a4540;
   padding-right: 10px;
   margin-right: 5px;