Rewrite description

[nataliecardot]

Improved readability, addressed grammatical/spelling errors. Also replaced code snippets with bolding for terms.

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)
• My pull request targets the master branch of freeCodeCamp.
• None of my changes are plagiarized from another source without proper attribution.
• All the files I changed are in the same world language (for example: only English changes, or only Chinese changes, etc.)
• My changes do not use shortened URLs or affiliate links.

Closes #XXXXX

[RandellDawson]

@nataliecardot When making changes to html for curriculum challenges, you need to be set up locally to validate what the change will actually look like. You can not use normal markdown like you can for Guide articles. See the curriculum challenge styling guide in the docs folder for more information. If you really want to bold text, you should be using <strong>...</strong> syntax. Can you please make a sreenshot of how your changes look as tested locally?

Thank you.