docs: add GitHub CLI tutorial (English)

[shreyaajahan]

Adds a new tutorial github-cli-tutorial-english.md that explains how to use GitHub CLI (gh) + git to fork, clone, branch, commit, push and open a PR.
Helps beginners contribute using the command line and documents an easy workflow for Windows / PowerShell users.
Files changed: [github-cli-tutorial-english.md]
How to test:
Clone your fork or checkout this branch locally
Open github-cli-tutorial-english.md and follow the copy‑paste commands under the "Expanded examples" section.
Checklist:
Documentation added
Screenshots included (optional)
I followed the repository contribution guidelines
Notes / Screenshots:
(Optional) Add screenshots here or mention that they are referenced from the project site.
If this PR closes an issue, add: Closes #

[rammba]

Hello @shreyaajahan, there is already similar guide in github-cli-tutorial.md. If you want to improve it, please change that file instead of creating a new one.