Add a link to the nav image

[YoshithaRathnayake]

Purpose

The purpose of this PR is to fix #38

Goals

Adding a link to the nav image

Approach

I added a link to the nav image

Screenshots

Preview Link

https://yoshitharathnayake.github.io/sack-blog/

Checklist

• [x] This PR doesn't commit any keys, passwords, tokens, usernames, or other secrets.
• [ ] I have read and understood the development best practices guidelines
• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation

Related PRs

## Test environment ## Learning

[Hasthikagirihagama]

@YoshithaRathnayake Also make sure to have the commit message matching to the issue and the PR