Add "Branch workflow"

[vjik]

Q	A
Is bugfix?	❌
New feature?	✔️
Breaks BC?	❌

[what-the-diff[bot]]

PR Summary

• Removal of Outdated Content The file 006-git-commit-messages.md was deleted. It became obsolete and was no longer required.

• Introduction of Improved Guidelines A new file, 006-git.md was added. This document provides enhanced instructions for the team's branch workflow and commit messages, increasing efficiency and clarity within the team.

• Update to Main Instructions The primary reference file, README.md was updated. It now correctly points to our new guide 006-git.md, ensuring all team members access the most recent and relevant workflow guidelines.

[vjik]

Awaiting result of experiment with new branches workflow in Yii Strings.