Fix typo in README

[MeetBera]

Link to the curriculum page

https://github.com/CodeYourFuture/HTML-CSS-Module-Project

Steps to reproduce

There is a small typo in the README file.

Steps:

1. Open README.md
2. Look at the introduction section
3. A word is misspelled

Expected:
Correct spelling

Actual:
Typo present

[nightcityblade]

Hi, I'd like to work on this. I'll submit a PR shortly.