mkfs: add page

[johncurcio]

• The page (if new), does not already exist in the repo.
• The page is in the correct platform directory (common/, linux/, etc.)
• The page has 8 or fewer examples.
• The PR title conforms to the recommended templates.
• The page follows the content guidelines.

Relates to #2214

[tldr-bot]

The build for this PR has failed with the following error(s):

pages/linux/mkfs.md:4: TLDR003 Descriptions should start with a capital letter

Please fix the error(s) and push again.

[agnivade]

Thanks for the PR. Got a few minor comments.

[sbrl]

Thanks, @johncurcio!

A teensy thing would be that perhaps Create might sound batter than Build, but I think it's fine either way.