Create matchAll.md

[raym293]

Description

Added matchAll/matchAll.md following the style guides in the required folder.

Issue Solved

#6955

Type of Change

• Adding a new entry
  - Editing an existing entry (fixing a typo, bug, issues, etc)
• Updating the documentation

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]

Thank you for contributing to Codecademy Docs @raym293 😄

The entry looks good for a second round of review! 🚀