Add missing photon_sample_fraction parameter to QED block#4

TomGoffrey merged 1 commit intoepochpic:mainepochpic/epochpic.github.io:mainfrom

JoelLucaAdams:qed_photon_sample_fractionJoelLucaAdams/epochpic.github.io:qed_photon_sample_fractionCopy head branch name to clipboard