Some of the major differences can be found in the changelog here in Steam. If you click on changelogs for versions you can see the initial upload has quite a big changelog entry. This doesn't necessarily include all changes but should contain the most important stuff.

Most notably there are more provinces, more tags and some tweaks to make the game a little bit more hardcore (such as increased damage from looting and trade centers not trading if occupied or blockaded).

What is the major difference between the Traveler Edition and Meiou 3.0?

Where can I read the specific changes?