Include user docs in readme & settings page

Author: zaelgohary

README.md

@@ -4,6 +4,10 @@
 
 Threefold Connect is a mobile app that serves as your main gateway to the Threefold Grid and various other Threefold products and services.
 
+## Documentation
+
+For detailed user documentation and guides, please visit the [TFConnect User Guide](https://manual.grid.tf/labs/documentation/tfconnect_toc).
+
 ## App
 
 ## Local development

app/lib/screens/preference_screen.dart

@@ -224,6 +224,11 @@ class _PreferenceScreenState extends ConsumerState<PreferenceScreen> {
             title: const Text('Terms and conditions'),
             onTap: () async => {await _showTermsAndConds()},
           ),
+          ListTile(
+            leading: const Icon(Icons.help_outline),
+            title: const Text('View Documentation'),
+            onTap: () async => {await _showDocumentation()},
+          ),
           ListTile(
             leading: const Icon(Icons.logout_outlined),
             title: Text(
@@ -459,6 +464,15 @@ class _PreferenceScreenState extends ConsumerState<PreferenceScreen> {
     await launchUrl(Uri.parse(url));
   }
 
+  Future<void> _showDocumentation() async {
+    const String url = 'https://manual.grid.tf/labs/documentation/tfconnect_toc';
+
+    final Uri uri = Uri.parse(url);
+    if (await canLaunchUrl(uri)) {
+      await launchUrl(uri, mode: LaunchMode.externalApplication);
+    }
+  }
+
   void _showVersionInfo() {
     try {
       AppConfig appConfig = AppConfig();