Making a PDF of a Google Doc is trivial. Just go to File->Download As->PDF. This will save a copy of the document as a PDF on your local machine. To share this PDF, add it back to Google Drive. Go to your game design folder (you do have a game design folder, right?), and click the New button, and choose File Upload. Choose the PDF you just downloaded and click ok. Once it appears in your game design folder, right click the file and select “Get Shareable Link”. Copy the link that pops up and that’s it. Test out the link by opening an Incognito window and paste the link in, to make sure it opens the PDF directly.