minor fixes to docsite root URLs (#28945)

* fix hardcoded http schemes to use relative URLs
* add doc fragment to version selector link to scroll target directly to the selector

docs/docsite/_themes/srtd/layout.html

@@ -140,7 +140,7 @@
         </ul>
     </div>
 
-  <a class="DocSite-nav" href="http://docs.ansible.com/">
+  <a class="DocSite-nav" href="/">
     <img class="DocSiteNav-logo"
       src="{{ pathto('_static/', 1) }}images/logo_invert.png"
       alt="Ansible Logo">
@@ -155,7 +155,7 @@
     <nav data-toggle="wy-nav-shift" class="wy-nav-side">
 
       <div style="background-color:#5bbdbf;height=80px;margin:'auto auto auto auto'">
-        <a class="DocSiteProduct-header DocSiteProduct-header--core" href="http://docs.ansible.com">
+        <a class="DocSiteProduct-header DocSiteProduct-header--core" href="/">
             <div class="DocSiteProduct-productName">
                 <div class="DocSiteProduct-logoText">
                     Ansible  
@@ -167,7 +167,7 @@
         </a>
         
 
-          <div class="DocSiteProduct-CheckVersionPara">For previous versions, see the  <a class="DocSiteProduct-versionheader" href="http://docs.ansible.com/">documentation archive.</a></div> 
+          <div class="DocSiteProduct-CheckVersionPara">For previous versions, see the  <a class="DocSiteProduct-versionheader" href="/#coreversionselect">documentation archive.</a></div>
       </div>
 
       <div id="menu-id" class="wy-menu wy-menu-vertical" data-spy="affix">