All methods are fairly self explanatory, and reading the godoc page should explain everything. If something isn't clear, open an issue or submit a pull request.
The scope of this project is just to provide a wrapper around the API without any additional features. There are other projects for creating something with plugins and command handlers without having to design all that yourself.
Please take a look at examples/example.go.
Run it using:
cd examples/
go run example.go -token <your-token>