Edit - CSS - sepia.md

[danitellini]

Description

Topic: Edit - CSS - Filter Funtions - sepia.md
File Edited: docs/content/css/concepts/filter-functions/terms/sepia/sepia.md
Files Added: docs/media/sepia-example-original.jpg and docs/media/sepia-example-filtered.jpg
Closes an open issue

Issue Solved

Closes #4869

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.