Upload the screenshots to a hosting site such as photobucket. In the bottom right corner of the message box you'll see a button that says "insert other media" then "insert image from URL" then find the ragepluginhook.log in your main GTAV directory, open with notepad, copy the text, come back here hit the "eye" icon at the top there to post a spoiler, copy said text into said spoiler (can do the same with the screenshots if you want) then you'll be good.