Fix GitHub capitalization in README installation section

[DanChaltiel]

Motivation

• Fix incorrect capitalization of the GitHub brand name in the Installation section to improve documentation quality.
• Ensure consistency of branding and reduce minor typos in the repository README.

Description

• Replaced the string "Github" with the correctly capitalized "GitHub" in the README.md Installation code block.
• The change is documentation-only and touches only the README.md file.

Testing

• No automated tests were run because this is a documentation-only change.

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Codex Task