[FEATURE] Improve and Modernize Footer Design

### Is your feature request related to a problem? Please describe.

Currently, the footer on ZettaNote feels minimal and lacks professional polish. It doesn’t provide key information or design consistency with the rest of the site’s interface.

### Describe the solution you'd like

I would like to introduce a redesigned, more professional footer that includes:

Clear branding (logo, name, tagline)
Quick navigation links (Home, About, Docs, Contact, etc.)
Social media and GitHub repository links
Copyright notice and year (automatically updated)
Subtle styling (consistent color scheme, spacing, and typography)
This will enhance the overall user experience and visual consistency across the site.

### Describe alternatives you've considered

_No response_

### Additional context

A new footer could also include a light/dark theme adaptation to maintain consistency across themes.