Add first draft of MarkdownDisplay component

[nchaloult]

Related to #9, but doesn't quite close it.

This PR introduces a MarkdownDisplay component on the front-end that displays the generated "tree printout" describing the directory structure of a public GitHub repo.

Implemented Functionality

• Displays lines that are passed in through a list of strings as a prop
• "Copy to Clipboard" button is present, copying all of the contents displayed
  • Brought in react-copy-to-clipboard for this
    • I bet you that there's a better way to implement this functionality that doesn't depend on a third-party module. What does everybody think?
  • Calls .join('\n') on the list of strings prop, then copies that result to the user's clipboard

Stuff Not Implemented

• It looks like 💩 atm

  • 10 is all about addressing this

    

[ralph-dev]

@nchaloult What is this?

[ralph-dev]

Why aren't we using the existing markdown styling :P

[nchaloult]

@ralph-dev What do you mean by existing markdown styling?

[ralph-dev]

@nchaloult Like why not use the styles that we already have rather than make a new one? Or are we planning to merge this than style it with the existing style we had earlier?

[nchaloult]

Right, this PR doesn't have anything to do with style. I abstracted away the Markdown "tree printout" display box into its own component like we talked about doing in one of our video calls on Wednesday. This PR only introduces functionality for the new display box component.

[ralph-dev]

Styles always go at the bottom of the document btw

[nchaloult]

Styles always go at the bottom of the document btw

Oh, I didn't know that. I learned something new! 😎 The linter I've always used complains if I use things before they're defined in a file. Thanks for letting me know 😃

I'll throw a new commit onto the markdown-display-component branch that moves those styled components tomorrow morning.