Pet.jsx : UI improve

[biswajit-sarkar-007]

In the /pet section, some UI improvements are needed:

1. There should be proper spacing between the selector tag and the dog cards (boxes).
2. The cat image and the New Cat button should be positioned one below the other.
3. All sections are currently left-aligned; centering them on the screen would enhance visibility.
4. The heading texts Dog & Cat Images and Favorites should have some added styling.

[biswajit-sarkar-007]

@UrekMaz please add the Hacktoberfest label.

[venisha-kalola]

this issue already exists