Added shapes and lines Module. Issue No #40

[Vaibhav2154]

Description:

Added a new module for "Shapes & Lines" to enhance the learning experience of the app users. This module provides interactive content to educate users about different shapes and lines.

Changes Made: Created a new Dart file named lines.dart within the pages directory to host the Shapes & Lines page. Implemented the UI layout for the Shapes & Lines page, including text descriptions and placeholders for various shapes and lines. Updated the routes.dart file to include a new route constant (linesRoute) for the Shapes & Lines page. Integrated the Shapes & Lines page into the main app (main.dart) by importing the page file and adding the new route to the routes map in the MaterialApp widget. This pull request enhances the educational content of the app and improves user engagement by adding a new module focused on shapes and lines. Future iterations may include further enhancements to the UI and interactive features within this module.

[sapatevaibhav]

The page is there from the beginning. Add the details (Shapes and lines) to that page...