adds styleguide markdown file

[LDNCWRB]

What changes have you made?

• adds styleguide mardown file - empty for now

Which issue(s) does this PR fix?

Fixes #3

Screenshots (if there are design changes)

How to test

[Jbarget]

can we add one thing to the styleguide that over the years i've found to be a good way of writing react components:

React component structure

// imports
import blah from "blah-blah"

// types
interface ButtonProps {
  onClick: () => void;
  label: string
}

// component
const Button - (label) => {
  return ( 
    ...button component...
  )
}

// export default
export default Button