Nutrients are replaced with nutrient solution
Small changes concerning balance, gameplay, or graphics.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Things related to oil and other fluids.
Furnaces, assembling machines, production chains.
The changelog is not accessible from the "changelog" button in the in-game mod menu. I believe this is because your changelog file is missing the https://wiki.factorio.com/Tutorial:Mod_changelog_format#Version_section_start at the very first line of the file.
See also: https://wiki.factorio.com/Tutorial:Mod_changelog_format#Example_changelog
Thanks, added the missing line.