Update setup.sh

Edited broken command "sed ...shared_buffers = ..." line 28
Merge branch 'master' of github.com:patch-engineering/set-up
added ffmpeg link and placeholder
updated Readme with ffmpeg instructions and added the 'symlink-handlebars' step as well
markdown changes
markdown changes, added compiling Patchy app
markdown changes, added compiling Patchy app
didnt cd migrate to migrations early enough, sending changes in script now
edited README
updated Readme