Currently the changelog is not visible ingame: https://wiki.factorio.com/Tutorial:Mod_changelog_format
Please also note that the latest version according to the changelog will conflict when you get to the 12th bugfix for 0.3
Version: 0.3.1 (dev-2) => 0.3.12 => Version 0.3 Bugfix 12
You should only increase the latest bugfix version number, so factorio will update the mod correctly. (e.g. if you release 0.3.2, it will not update or load it because a newer version 0.3.12 already exists.) Each number between the dots is checked separately.