fix: adding proper command for extracting archives

[HicaroD]

Description of what this PR is changing or adding, and why:

Some commands for extracting files were wrong in the documentation. So I fixed these commands for Linux and macOS. For some weird reason, some flags, such as -C from tar command, were not showing, so I used multilines as a sorta of hack in order to make these flags appear, so I hope it is not a problem.

Also I removed the word zip from the description because the downloaded artifact may not be a zip file, therefore it could cause a slight confusion to the user, in my opinion.

Issues fixed by this PR (if any):
#10607

Presubmit checklist

• This PR doesn’t contain automatically generated corrections (Grammarly or similar).
• This PR follows the Google Developer Documentation Style Guidelines — for example, it doesn’t use i.e. or e.g., and it avoids I and we (first person).
• This PR uses semantic line breaks of 80 characters or fewer.

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[atsansone]

@HicaroD : Good catch! If you can sign the CLA, we can get this merged.

• Fixes #10575
• Fixes #10607
• Fixes #10614

[atsansone]

/gcbrun

[flutter-website-bot]

Visit the preview URL for this PR (updated for commit 5b3971f):

https://flutter-docs-prod--pr10610-fix-10607-59pskxc9.web.app

[HicaroD]

I'm happy to contribute!

Thanks for reviewing @atsansone

[sethladd]

Thanks for the contribution!