Fixed: Same key warning in console issue in image grid component

[SaurabhSonde]

This PR resolves #206

Description

two children with same key warning issue is fixed in this pr.I have added a index to key prop.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] All new and existing tests have passed and it does not give any unexpected error for the same.

[SaurabhSonde]

I would request @charithccmc, @wdevon99 and @Grumpyyash to please review this PR.