The game gets semi-regular updates, each of which expand the story by a big chunk. They are not officially named but just have a version number: 0.1, 0.2, 0.3... The most recent version is 0.7.
While the game doesn't subdivide itself into chapters, the community kinda does. For example, all the content that got added in version 0.2 is part of chapter 0.2
The segment that you've described is in the first half of chapter 0.3