realtime: Fix image broken link (supabase#31248)

Author: filipecabaco

apps/docs/content/guides/realtime/migrate-from-postgres-changes.mdx

@@ -17,8 +17,8 @@ We store this information in a `public.moves` table and every time a new move is
   alt="Schema used for our example"
   src={{
     light:
-      'docs/public/img/guides/realtime/realtime-broadcast-changes-migration-schema-example-light.png',
-    dark: 'docs/public/img/guides/realtime/realtime-broadcast-changes-migration-schema-example-dark.png',
+      '/docs/img/guides/realtime/realtime-broadcast-changes-migration-schema-example-light.png',
+    dark: '/docs/img/guides/realtime/realtime-broadcast-changes-migration-schema-example-dark.png',
   }}
 />