docs: Fix docs' styling conflict with common names

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)

Closes issue #6329

docs/theme/mkdocs/base.html

@@ -66,7 +66,7 @@
     </div>
   </div>
 
-  <div id="push"></div>
+  <div id="push-footer"></div>
 
 </div>
 

docs/theme/mkdocs/css/main.css

@@ -305,7 +305,7 @@ body {
   margin: 0 auto -379px;
 }
 /* Set the fixed height of the footer here */
-#push,
+#push-footer,
 #footer {
   height: 379px;
   background: #253237;