mo(contributing): add Write a User Story for a new feature section
feat(generator): generate cards using a template but without formatting

Issue #2
mo(readme): explain how to generate cards
tpl(fototse): add The Machine back card
mo(readme): add Guillaume Royer to Lead contribution team
mo(readme): add generation destination folder

Also add list of templates to generate
mo(contributing): fix hidden user story example cause of format
mo(readme): structure better readme
tpl(fototse): fix the machine back picture greyscale