In Extension:PieceOfCode I gave the readme parameter a value, but it just appears as an unidentified link under Download. I assume the same is true for changelog. The easy fix would be to provide link text for each, same as "Browse source code"
But with all these links, you're not downloading anything., so none belong under a Download column! They're just links to files that probably reflect the latest code, and the infobox seems to conflate this with "snapshot". It seems there should be a separate infobox section for Project, with links in it for browse source, view changes, readme, and changelog.