[Feature]: Adding Focused navlink in navbar

[SHRIVISHNU-CM]

@abhishekraoas adding a new feature that is a focused nav link in the navbar to enhance the UI of the website. If user visit particular section navlink in the navbar will be focused.
Please assign this task to me. GSSOC's 2024 EXTD

[agarwalhimanshugaya]

@SHRIVISHNU-CM ok u can work on it