docs(integrations): add missing Gotify integration page

The Gotify integration (merged from dev) declares a documentationUrl but
had no docs page, failing the docs-coverage validation plugin once gotify
was added to the integration doc-slug map.

apps/docs/docs/integrations/gotify/index.ts

@@ -0,0 +1,8 @@
+import { IntegrationDefinition } from "@site/src/types";
+
+export const gotifyIntegration: IntegrationDefinition = {
+  name: "Gotify",
+  description: "Gotify is a simple server for sending and receiving messages in real time via push notifications.",
+  iconUrl: "https://cdn.jsdelivr.net/gh/homarr-labs/dashboard-icons/svg/gotify.svg",
+  path: "../../integrations/gotify",
+};