docs: changes to deployment + remove admin deployment guides (#10345)

* docs: change headings and text in deployment

* remove admin deployment guide

* generate changes

www/apps/resources/sidebar.mjs

@@ -2159,7 +2159,7 @@ export const sidebar = sidebarAttachHrefCommonOptions([
           },
           {
             type: "category",
-            title: "Medusa Application",
+            title: "Self-Hosting",
             children: [
               {
                 type: "link",
@@ -2173,11 +2173,6 @@ export const sidebar = sidebarAttachHrefCommonOptions([
               },
             ],
           },
-          {
-            type: "category",
-            title: "Medusa Admin",
-            autogenerate_path: "/deployment/admin",
-          },
           {
             type: "category",
             title: "Next.js Starter",