Update folder structure

[jnywong]

Closes #72

Note that I have rebased the folder restructure onto the commit a8556f1, so please double-check the files changed in case I missed anything :)

[JFormoso]

Hi! Thank you!

I don't know what the intro.md file is but it makes sense that it will eventually be home.

I noticed you changed:

for:

I used HTML instead of markdown because the image was too big and I didn't know how to adjust the size with md. I approved the changes, let me know if I have to do anything else.

[jnywong]

I noticed you changed:

for:

That's a small detail that won't affect the folder structure, so I will merge now to unblock @kvenkman and we can tweak this bit afterwards 👍