Add cpp unordered set reverse

[dejongbaba]

Description

[Term Entry] C++ Unordered sets end function: reserve()

Issue Solved

Closes #8050

Type of Change

• Adding a new entry

Checklist

• All writings are my own.
• My entry follows the Codecademy Docs style guide.
• My changes generate no new warnings.
• I have performed a self-review of my own writing and code.
• I have checked my entry and corrected any misspellings.
• I have made corresponding changes to the documentation if needed.
• I have confirmed my changes are not being pushed from my forked main branch.
• I have confirmed that I'm pushing from a new branch named after the changes I'm making.
• I have linked any issues that are relevant to this PR in the Issues Solved section.

[mamtawardhani]

Hey @dejongbaba, the entry looks good! 😄

Could you please remove the querySelectorAll.md file from this branch? Thanks!

[dejongbaba]

Hey @dejongbaba, the entry looks good! 😄

Could you please remove the querySelectorAll.md file from this branch? Thanks!

Hi @mamtawardhani, thank you for your response, I've removed it from the branch, you can see it in this commit b9b1580
or is there something I'm missing? hopefully its fine and my update can be merged because this is the second time you're pointing this out and my previous PR 8091 has not been merged yet as well, I want to get this out of the way as soon as possible. Let me know what to do, thank you.