Removed unused files, code cleanup

lib/features/app_intro/widgets/welcome_intro_slide.dart

@@ -1,27 +0,0 @@
-import 'package:flutter/material.dart';
-
-class WelcomeIntroSlide extends StatelessWidget {
-  const WelcomeIntroSlide({super.key});
-
-  @override
-  Widget build(BuildContext context) {
-    return Column(
-      children: [
-        Text(
-          "Welcome to Paperless Mobile!",
-          textAlign: TextAlign.center,
-          style: Theme.of(context).textTheme.titleLarge,
-        ),
-        Padding(
-          padding: const EdgeInsets.all(16),
-          child: Text(
-            "Manage, share and create documents on the go without any compromises!",
-            textAlign: TextAlign.center,
-            style: TextStyle(color: Theme.of(context).hintColor),
-          ),
-        ),
-        Align(child: Image.asset("assets/logos/paperless_logo_green.png")),
-      ],
-    );
-  }
-}