[Landing page] Change Upgrade to Upgrade versions (#1382)

Author: KOTungseth

src/Elastic.Markdown/Slices/Layout/_LandingPage.cshtml

@@ -16,7 +16,7 @@
 						Get started
 					</a>
 					<a href="@Model.Link("/deploy-manage/upgrade")" class="grow cursor-pointer text-blue-elastic hover:text-blue-elastic-100 text-nowrap border-2 border-blue-elastic hover:border-blue-elastic-100 focus:ring-4 focus:outline-none focus:ring-blue-elastic-50 font-semibold font-sans rounded-sm px-6 py-2 text-center h-10 flex items-center justify-center">
-						Upgrade
+						Upgrade versions
 					</a>
 				</div>
 			</div>