Add missing Manchester picture

### Link to the page

https://github.com/CodeYourFuture/github_issues_prs_practice

### Steps to reproduce

1. Navigate to the website
2. The image for Manchester on the second row is missing.

Start at the linked repository and inspect the website's second row to find the Manchester entry and its missing image reference. Add the missing Manchester picture, then verify by navigating to the website and confirming the image appears in the second row.

由索引模型根据 Issue 内容生成。