chore: choose a CSS architecture metodology

[ItsCrisDiaz]

Summary

Define which of the suggested CSS architecture patterns we'll use for Booking System

Acceptance criteria

• [x] Define the CSS paradigm we want to apply to this project (Functional, Semantic, a mix of both)
• [x] Define the CSS methodology we should use for this project (Atomic Design, OOCSS, SMACSS, BEM, CUBE CSS)
• [ ] Abstract what kind of design elements we can express as utility classes

[701i]

Hi, there are some task that looks like these issues: We can work together https://github.com/Platzi-Master-C9/booking-ui/issues/4 https://github.com/Platzi-Master-C9/booking-ui/issues/45