Folder structure and clean code

[abhirock1998]

• Remove warning from terminal
• Use only js or jsx extension file
• need to remove the default image and file from the public folder
• hook always needs to declare on the top of the component
• Remove uncomment code
• Redundant conditional render in toggler.js file
• Move material UI styles into another file for clean code
• export all components and pages from a single file instead of exporting separately
• Add secrets into .env file instead of using them directly for security purposes