Add alt attributes to images in templates

[Dippp10]

@Divyanshi Kulshrestha ji

Many images under templates/ or in static assets don’t have alt text. For accessibility and SEO, i would ensure all tags include meaningful alt descriptions (e.g. site logo, event images, icons).

[Dippp10]

@ Divyanshi Kulshrestha ji, i have created above issue number 119.....do assign mentors to it and GSSoC'2025 label, level 1 label to it....do assign the issue number 119 to me