Expose the Folders view

This adds a new 'Folders' screen which shows you all your folders and
lets you manage the notes inside them. It currently doesn't allow you to
add or remove Folders, though.

This nearly addresses #18

lib/app.dart

@@ -20,6 +20,7 @@ import 'package:dynamic_theme/dynamic_theme.dart';
 
 import 'screens/githostsetup_screens.dart';
 import 'screens/onboarding_screens.dart';
+import 'screens/folder_listing.dart';
 
 class JournalApp extends StatelessWidget {
   static Future main(SharedPreferences pref) async {
@@ -120,6 +121,7 @@ class JournalApp extends StatelessWidget {
       initialRoute: initialRoute,
       routes: {
         '/': (context) => HomeScreen(),
+        '/folders': (context) => FolderListingScreen(),
         '/settings': (context) => SettingsScreen(),
         '/setupRemoteGit': (context) =>
             GitHostSetupScreen(stateContainer.completeGitHostSetup),

lib/screens/home_screen.dart

@@ -2,7 +2,6 @@ import 'package:flutter/material.dart';
 import 'package:gitjournal/state_container.dart';
 
 import 'journal_listing.dart';
-import 'folder_listing.dart';
 
 class HomeScreen extends StatelessWidget {
   @override
@@ -10,7 +9,6 @@ class HomeScreen extends StatelessWidget {
     final container = StateContainer.of(context);
     final appState = container.appState;
 
-    return JournalListingScreen(noteFolder: appState.noteFolder);
+    return JournalListingScreen(notesFolder: appState.notesFolder);
-    // return FolderListingScreen();
   }
 }

lib/widgets/app_drawer.dart

@@ -57,6 +57,31 @@ class AppDrawer extends StatelessWidget {
             ),
           ),
           setupGitButton,
+          ListTile(
+            leading: Icon(Icons.note, color: textStyle.color),
+            title: Text('Notes', style: textStyle),
+            onTap: () {
+              var m = ModalRoute.of(context);
+              if (m.settings.name == "/") {
+                Navigator.pop(context);
+              } else {
+                Navigator.pop(context);
+                Navigator.pushReplacementNamed(context, '/');
+              }
+            },
+          ),
+          ListTile(
+            leading: Icon(Icons.folder, color: textStyle.color),
+            title: Text('Folders', style: textStyle),
+            onTap: () {
+              var m = ModalRoute.of(context);
+              if (m.settings.name == "/folders") {
+                Navigator.pop(context);
+              } else {
+                Navigator.popAndPushNamed(context, "/folders");
+              }
+            },
+          ),
           ListTile(
             leading: Icon(Icons.share, color: textStyle.color),
             title: Text('Share App', style: textStyle),