feat(css): add new term for margin-block property

[dzevad-cyber]

Description

Adds the new term for the margin-block property.

Issue Solved

issue #8215

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 @dzevad-cyber, the PR looks good. However, could you please add the output images in this PR and place the images in the media folder in docs?

Let me know once done. Thanks!

[dzevad-cyber]

Hey @dzevad-cyber, the PR looks good. However, could you please add the output images in this PR and place the images in the media folder in docs?

Let me know once done. Thanks!

Hey @mamtawardhani, i've uploaded output images to the docs/media folder as requested. Let me know if you need any other changes. Thanks!