Add user stories and wireframes from eLife Sprint to this repo

[npscience]

It would be useful to capture:

• the user stories in the etherpad as a .md here (in case someone deletes all the text in the etherpad). I have made this .md already and can PR this to you to review.
• the wireframe diagrams — I can make a folder of the images in your eLife Sprint slides and PR these to you here too.

Are you happy for me to go ahead? If so, how would you like the folder structure to be like?

e.g. I would propose:
~/Design
|_ 'UserStories.md'
|_ /wireframes
|'Mockup_main_page.jpg'
| (etc)

Just let me know and I'll PR away :) (if so, who should I assign to review?)

[npscience]

Update:

• .md for (i) above sent to @dasaderi via Sprint slack
• Nick has sent .zip of all design assets to same Slack