docs: Enhance FAQ with Miniflux 2.2.18 network access info

Updated FAQ section with new details on Miniflux network access requirements.

Author: Qetesh

README.md

@@ -100,7 +100,8 @@ docker-compose up -d
 
 ## FAQ
 <details>
-<summary>If the formatting of summary content is incorrect, add the following code in Settings > Custom CSS:</summary>
+<summary> If the formatting of summary content is incorrect, add the following code in Settings > Custom CSS: </summary>
+
 ```
 pre code {
     white-space: pre-wrap;
@@ -109,6 +110,20 @@ pre code {
 ```
 </details>
 
+<details>
+<summary> fetcher: refusing to access private network host "xx.xx.xx.xx" </summary>
+
+Starting with Miniflux 2.2.18, `FETCHER_ALLOW_PRIVATE_NETWORKS=1` must now be enabled to access feeds hosted on a local network. See the [official release notes](https://github.com/miniflux/v2/releases/tag/2.2.18) for details.
+
+</details>
+
+<details>
+<summary> level=WARN msg="Unable to send new entries to Webhook" ... client: connection to private network is blocked: host "miniflux-ai" resolves to a non-public IP address" </summary>
+  
+Starting with Miniflux 2.2.18, `INTEGRATION_ALLOW_PRIVATE_NETWORKS=1` must now be enabled to access third-party integration services hosted on a local network. See the [official release notes](https://github.com/miniflux/v2/releases/tag/2.2.18) for details.
+
+</details>
+
 ## Contributing
 
 Feel free to fork this repository and submit pull requests. Contributions and issues are welcome!