Fix 404 link though adding a README file

[jason-vasilev]

Saw a 404 link in Foundation final project for Flipping Card game where it says "which you can find here"

Seemed like we were getting a README file in the link through the build process, as before that, it was not in the source code. Didn't know how to fix it, so instead just made a file that embeds the assets

[shpomp]

Good catch! ⭐

[shpomp]

I am not sure what sense it makes to provide a card picture, as they will have to find more on their own anyway and might want to choose a theme themselves - so I think this should be corrected.
Perhaps we can then just give a short comment and link to the backside pattern itself?

Suggested change

	You are provided with a card picture and a card backside image which you can use, [which you can find here](./assets/card/README.md), or feel free to choose your own.
	Find a few pictures to use for your game. Consider if you would use random images or make your game themed.
	Use [this](./assets/card/card-backside.jpg) card backside image, or find/create your own.

[adamblanchard]

I think because the first exercise is focussed on just making it flippable, it's nice to give them two assets to get started with asap. We do write that they are free to choose their own. You're right they will have to find their own later anyway, i think it's ok to leave it up to them then.

I am not in the session though, if it was not so smooth in the session i'm happy to leave it up to you/mentors who saw it in action :-)

[shpomp]

that makes sense, thanks for explaining @adamblanchard!
I created this, I should have remembered :D

[adamblanchard]

I took over a bit here to fix the linting.

Also, i forgot, but if we want the page to render in gitbook (ie. on program.hackyourfuture.com) nicely, we also need to add the page to the sidebar, otherwise gitbook will link it externally (and go directly to the github source). I made that commit too.