Clarify default directory for `gh classroom clone student-repos`

[aniruddhaadak80]

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What article on docs.github.com is affected?

https://docs.github.com/en/education/manage-coursework-with-github-classroom/teach-with-github-classroom/using-github-classroom-with-github-cli

What part(s) of the article would you like to see updated?

The gh classroom clone student-repos description says:

By default, the student repositories are cloned into the current directory a directory named after the assignment slug.

The sentence is missing in, which makes the default destination ambiguous. The following sentence also says If the directory does not exists, rather than If the directory does not exist.

The expected wording should describe that the command clones the repositories into a directory named after the assignment slug within the current directory by default, and should use correct subject-verb agreement.

Additional information

The GitHub Classroom CLI source documents this behavior in its command help:

By default, the student repos are cloned into the current directory in a directory named after the assignment slug.

The implementation joins the selected directory with assignment.Slug+"-submissions", confirming the default destination. No existing issue or pull request covers these two errors in the current article.

[subatoi]

Since I've just accepted #46050 (but it's not linked), I'll go ahead and close this out manually, thank you