Add new page for cherry-picking with Git

What does this MR do and why?

In this MR, a new page for Cherry-pick changes with Git is created. It will be a child page inside the Use Git --> Advanced operations section.

The information on this page is Git-related info from the Cherry-pick changes page and other relevant git cherry-pick content.

It is part of a larger issue to reorganize Git documentation to improve the user experience by separating GitLab UI and Git CLI tasks.

Navigation

- Advanced operations
   - Rebase and resolve conflicts
   - Cherry pick changes
   - Revert changes
   - Tutorial: Update Git remote URLs

Review app

• NEW [Cherry-pick changes with Git]

Related issues

• Issue: #499459
• Child item: #499467
• MR to update navigation: Draft: Add nav item for cherry pick with git page (gitlab-docs!5168)