docs: misc updates for extensions directory (#5035)

Co-authored-by: Amed Rodriguez <amed@squareup.com>

documentation/src/components/server-card.tsx

@@ -85,7 +85,7 @@ export function ServerCard({ server }: { server: MCPServer }) {
                   </div>
                 )}
 
-                {!server.is_builtin && (
+                {!server.is_builtin && (server.show_install_command !== false) && (
                   <>
                   <button
                     onClick={() => setIsCommandVisible(!isCommandVisible)}
@@ -139,7 +139,7 @@ export function ServerCard({ server }: { server: MCPServer }) {
                   >
                     Built-in
                   </div>
-                ) : (
+                ) : server.show_install_link !== false ? (
                   <a
                     href={getGooseInstallLink(server)}
                     target="_blank"
@@ -149,7 +149,7 @@ export function ServerCard({ server }: { server: MCPServer }) {
                     <span>Install</span>
                     <Download className="h-4 w-4" />
                   </a>
-                )}
+                ) : null}
               </div>
             </div>
           </div>