Protect main branch from pushes and change Git development model

[sampathbalivada]

It's a good practise to protect the main branch from direct pushes. Add branch protection rules for this

• Managing a branch protection rule

Also, consider using Trunk based changes or Gitflow for this repository.

• Trunk-based development

[psidh]

PR : #6

Commit : 50a36d8

have added a branch-protection rule to main branch

[psidh]

I added Contributing.md file