Stop copying changelog.txt to the website
Stop copying changelog.txt to the website

It's not referenced from the site itself, and the GitHub releases page is
nicer.

openseadragon/openseadragon,ricochet2200/openseadragon,avandecreme/openseadragon,TMUND/openseadragon,LarissaSmith/openseadragon,Iced-Tea/openseadragon,msalsbery/openseadragon,TMUND/openseadragon,seanich/openseadragon,Iced-Tea/openseadragon,sul-dlss/openseadragon,ricochet2200/openseadragon,lidasong2014/openseadragon,shaunstanislaus/openseadragon,jmnetus/openseadragon,shaunstanislaus/openseadragon,daverome/openseadragon,jmnetus/openseadragon,LarissaSmith/openseadragon,LafayetteCollegeLibraries/openseadragon,avandecreme/openseadragon,janelia-flyem/openseadragon,mcanthony/openseadragon,janelia-flyem/openseadragon,msalsbery/openseadragon,daverome/openseadragon,mcanthony/openseadragon,openseadragon/openseadragon,rdlester/openseadragon,goofwear/openseadragon,seanich/openseadragon,goofwear/openseadragon,lidasong2014/openseadragon,rdlester/openseadragon