write minimal scss to create grid layout and fill random colors

[satyam-seth]

• create new branch for new issue

git checkout -b task4

• add local changes

git add .

• commit local changes

git commit -m "leave your comment"

• push your change to remote

git push origin task4

• Click the below link to create a pull request
  to create a pull request you have to visit the repository page

• request the @satyam-seth to review the code