Accessibility Updates (#16633)

* Fixed accessibility issues in home page

Signed-off-by: ChaitanyaKaranam <karanam.krishna.25@gmail.com>

* Fixed accessibility issues for docs/home page

Signed-off-by: chaitanyakaranam <chaitanya.karanam@yahoo.com>

* Fixed accessibility issues for /partners page

Signed-off-by: chaitanyakaranam <chaitanya.karanam@yahoo.com>

* Fixed accessibility issues for /community page

Signed-off-by: chaitanyakaranam <chaitanya.karanam@yahoo.com>

* Update layouts/partials/header.html

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

* Update layouts/partials/footer-scripts.html

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

* Update layouts/index.html

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

* Update content/en/partners/_index.html

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

* Update content/en/community/_index.html

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

* Added missing quotes

* Added landmark roles for search bar and footer

Signed-off-by: chaitanyakaranam <chaitanya.karanam@yahoo.com>

* Changed images alt text

Changed alt text from 'kubernetes community' to 'Kubernetes Conference Gallery'

* Removed verb from iframe title

Signed-off-by: chaitanyakaranam <chaitanya.karanam@yahoo.com>

* Change alt text for GitHub image

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

* Few alt text changes

* Modified alt text

layouts/partials/footer.html

@@ -7,7 +7,7 @@
             {{ with site.GetPage "section" . }}<a href="{{ .RelPermalink }}">{{ .LinkTitle }}</a>{{ end }}
             {{ end }}
         </nav>
-        <div class="social">
+        <div class="social" role="region" aria-label="Social hyperlinks">
             <div>
                 <a href="https://twitter.com/kubernetesio" class="twitter"><span>{{ T "community_twitter_name" }}</span></a>
                 <a href="https://github.com/kubernetes/kubernetes" class="github"><span>{{ T "community_github_name" }}</span></a>
@@ -23,13 +23,13 @@
                 <a href="https://git.k8s.io/community/contributors/guide" class="button">{{ T "main_contribute" }}</a>
             </div>
         </div>
-        <div id="miceType" class="center">
+        <div class="miceType center">
             &copy; {{ now.Year }} {{ T "main_documentation_license" | safeHTML }}</a>
         </div>
-        <div id="miceType" class="center">
+        <div class="miceType center">
             Copyright &copy; {{ now.Year }} {{ T "main_copyright_notice" | safeHTML }}
         </div>
-        <div id="miceType" class="center">
+        <div class="miceType center">
             ICP license: 京ICP备17074266号-3
         </div>
     </main>