make contracts pdf for contracts lesson that isn't pathway specific

[flannery-denny]

make it in the contracts lesson then add the pdf to the lib folder "Makeworkbook.js" file add to line 20

const knownLongPages = [ 'flags-of-the-world-resource.pdf', 'SavingImagesGuide.pdf', 'infographics.pdf', 'animation-worksheet.pdf' ];

[schanzer]

Woohoo!! 🚀