added update instructions

Signed-off-by: fenn-cs <[email protected]>

Author: nfebe

README.md

@@ -1,2 +1,30 @@
 # phpList REST API swagger-ui
 OpenAPI Documentation for [phpList/rest-api](github.com/phpList/rest-api) ove Swaggger UI
+
+# Updating
+
+We use`swagger-ui-dist` which is the compiled version of swagger UI for server side projects. It's simply a copy of the `dist` directory from the[Swagger UI Repo](https://github.com/swagger-api/swagger-ui)) stored. 
+
+So if there are updates in the UI we would like to have, the fastest way to update our copy of swagger UI would be to clone the entire swagger UI [repository](https://github.com/swagger-api/swagger-ui) and copy the contents of `dist` to `public/docs` and make the required changes in `index.html`. That includes making sure the assets (javascript and css) are pointing to the right place (`/restapi-docs/`) and that `SwaggerUIBundle` is referencing `/restapi-docs/restapi.json` correctly as shown bellow;
+
+```js
+    window.onload = function() {
+      // Begin Swagger UI call region
+      const ui = SwaggerUIBundle({
+        url: "/restapi-docs/restapi.json",
+        dom_id: '#swagger-ui',
+        deepLinking: true,
+        presets: [
+          SwaggerUIBundle.presets.apis,
+          SwaggerUIStandalonePreset
+        ],
+        plugins: [
+          SwaggerUIBundle.plugins.DownloadUrl
+        ],
+        layout: "StandaloneLayout"
+      });
+      // End Swagger UI call region
+
+      window.ui = ui;
+    };
+```