Document the sync command with usage examples - hacktoberfest

[imharshtiwari]

This pull request adds documentation for the sync command to the ebook, providing an overview of its usage, syntax, examples, and available flags.

New documentation:

• Added a new section describing the purpose and usage of the sync command, including syntax and practical examples (ebook/en/content/138-the-syc-command.md).
• Included a table outlining additional flags for the sync command, detailing their functionalities (ebook/en/content/138-the-syc-command.md).

[Copilot]

Pull Request Overview

This PR adds comprehensive documentation for the sync command to the ebook, explaining its purpose for flushing filesystem buffers and providing practical usage examples. The documentation includes syntax, examples, and a reference table of available command flags.

• Added complete documentation section for the sync command with overview and usage examples
• Included syntax specification and practical command examples
• Added reference table detailing additional flags and their functionalities

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[bobbyiliev]

Thanks for this! Please take a look at the suggestions by the Copilot bot. And also make sure to update the chapter number as 138 already exists and add it ot the README file as well! Thank you.

[imharshtiwari]

Thanks for this! Please take a look at the suggestions by the Copilot bot. And also make sure to update the chapter number as 138 already exists and add it ot the README file as well! Thank you.

Changes has been modified

[bobbyiliev]

Thank you! You would also need to add a reference to that file in the README file please as it is done for all other chapters.