Enhance Performance and User Experience with `defer` Attribute and `meta` Theme Colour 🎨

[sanjaiyan-dev]

This pull request introduces two improvements to enhance the performance and user experience of our web page:

1. defer Attribute for External Scripts: Script tags with the defer attribute are executed after the HTML parsing is complete. This can improve the perceived loading speed of the page as the critical rendering path isn't blocked by external scripts.
2. meta Theme Color: Adding a meta tag with the theme-color property allows browsers and devices to pre-render a themed browser bar or tab, visually indicating the site before full load and enhancing user experience.(#eeeeee)

Benefits:

• Improved Perceived Performance: Deferring scripts ensures the HTML content renders first, leading to a faster initial page load experience for users.
• Enhanced User Experience: The theme-color meta tag provides a visual cue of the website's theme even before full load, increasing user engagement.