Add prereq info to Pomodoro project article

[Dusch4593]

Closes issue

• [x] My project tutorial topic has already been approved by the Codédex team
• [x] My project tutorial file renders properly in mdx
• [x] The content written is my own, and not plagiarized from other sources
• [x] All code written is commented or documented thoroughly
• [x] I have already completed a self-review of the project tutorial
• [x] I will comply with changes from the Codédex team about my project tutorial