Added: screen-reader optimized PDF and community copies

Hi! 

I've added a screen-reader-optimized PDF as a download. I hope everything is set up correctly (I've tested it on NVDA software and it worked for me but stuff happens). Let me know if it doesn't!

Also, from now on, every copy sold at the price of $5 or above adds one community copy. I've added 8 retroactively - one per each purchase at $5+. Tell your friends about us or something?