You're interested in contributing to this project, that's awesome!
The Xcode project is only included to support Carthage. You can still edit the files from the included Xcode project, but it does not include the tests, so it is recommended to open the root folder directly in Xcode so that it can recognize it as a Swift Package and allow running the tests.
There is only one dependency in the project, which is OHHTTPStubs. This is only used for testing.