Revert "add .gitignore file"

This reverts commit 26c7c52a248dc2f2146fe87d8b0a9788c75cf4bf.
Revert "Revert "add .gitignore file""

This reverts commit f3e6e48d8b617d8c7fe133d1c9d7ce031751769a.
add a sfml test file