[Git-Scm] Initial commit logic

[divineniiquaye]

Discussion

This pull request seeks to add a new Git SCM library into Poakium monorepo, which should be a lightweight library for working easily with git commands but must not include all features in git. So Prior git knowledge is required.

Closes issue #1

Motivation and context

Providing a lightweight library for writing PHP applications using git commands

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] Deprecation (un-wanted or renamed functionality that should be removed)
• [x] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to change)

PR checklist

• [x] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING.md document.
• [ ] I have added tests to cover my changes.

[divineniiquaye]

Git SCM is feature complete but ready to merge