git: update Spanish translation

[k-a-rthik]

I've used the EN version page of git.md and refreshed the outdated version of the ES git.md file. Verified the translations with another spanish speaker.

I am a high-school student learning Spanish (4th year) for my world language course.

If you are a new contributor to the project, do not use AI to generate pages. We will close any PR with a suspicion of AI usage.

• [ Yes] The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• [ Yes] The page description(s) have links to documentation or a homepage.
• [ Yes] The page(s) follow the content guidelines.
• [ Yes] The page(s) follow the style guide.
• [ Yes] The PR contains at most 5 new pages.
• [ Yes] The PR title conforms to the recommended templates.
• Version of the command being documented (if known): Most of the Git commands are supported from Git 1.0+, while git reset --hard is supported starting Git 1.8.0+

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