the default key bindings for format current buffer is `SPC b f`, and this key bindings is defined in [format layer](<>). you can also use `g=` to indent current buffer.
To make neoformat support go files, you should have [go-fmt](http://golang.org/cmd/gofmt/) command available, or
install [goimports](https://godoc.org/golang.org/x/tools/cmd/goimports). `go-fmt` is delivered by golang's default installation, so make sure you have correctly setup your go environment.