add sync API with swagger documentation at /api

README.md

@@ -2,7 +2,7 @@
 
 ## Overview
 
-"Sanasto Wiki" is a web-based dictionary application for simultaneous translators in the living Christianity. The application provides publicly accessible translations while restricting editing and commenting to invited contributors.
+"Sanasto Wiki" is a web-based glossary for simultaneous translators in the living Christianity. The application provides publicly accessible translations while restricting editing and commenting to invited contributors.
 
 ---
 
@@ -188,15 +188,25 @@ See 'public/Kristillisyyden sanasto ver 23.5.2013.xlsx'
 
 ---
 
-## API (Optional Future)
+## API (Public Sync)
 
-REST API for potential mobile app or integration:
+Public JSON endpoint for syncing entries:
 ```
-GET    /api/entries
-GET    /api/entries/:id
-GET    /api/entries/search?q=:query&lang=:code
-POST   /api/entries (authenticated)
-PATCH  /api/entries/:id (authenticated)
+GET /api/entries
+GET /api/entries?since=2026-01-01T12:00:00Z
+```
+
+Responses include all language columns, category and `updated_at`. The optional `since`
+parameter filters by `updated_at` (ISO8601).
+
+Swagger docs:
+```
+GET /api/swagger
+```
+
+Swagger UI:
+```
+GET /api
 ```
 
 ## Deployment