Document and test initial stylesheet props

[omariosouto]

Why

• Document: It's important to people see the available props and be aware that web supports everything while our list is related to props that are common in Flutter and React

How

• Use Flutter test for flutter and the Box component
• Use react testing library for react and the Box component
• Try to sync this docs inside storybook also
• inside "examples" add small examples related to the styled that are being created

DoD

• Have in skynexui.dev in the section "Stylesheet" all props properly documented