Tutorial doesn't compile on latest

[mattjohnsonpint]

No rush, but thought I'd point out that the tutorial in the readme doesn't work:

https://github.com/wundergraph/graphql-go-tools/blob/master/README.md#tutorial

The APIs have changed since it was originally created.

go build . gives:

./main.go:43:38: too many arguments in call to printer.Print
        have (*ast.Document, nil, *bytes.Buffer)
        want (*ast.Document, io.Writer)
./main.go:80:38: too many arguments in call to printer.Print
        have (*ast.Document, nil, *bytes.Buffer)
        want (*ast.Document, io.Writer)
./main.go:114:58: too many arguments in call to astprinter.PrintStringIndent
        have (*ast.Document, nil, string)
        want (*ast.Document, string)
./main.go:274:58: too many arguments in call to astprinter.PrintStringIndent
        have (*ast.Document, nil, string)
        want (*ast.Document, string)
./main.go:333:58: too many arguments in call to printer.Print
        have (*ast.Document, *ast.Document, *xxhash.Digest)
        want (*ast.Document, io.Writer)
./main.go:400:58: too many arguments in call to printer.Print
        have (*ast.Document, *ast.Document, *xxhash.Digest)
        want (*ast.Document, io.Writer)
./main.go:472:3: unknown field IncludeInfo in struct literal of type plan.Configuration
./main.go:480:13: assignment mismatch: 1 variable but plan.NewPlanner returns 2 values
./main.go:480:51: too many arguments in call to plan.NewPlanner
        have (context.Context, plan.Configuration)
        want (plan.Configuration)
./main.go:495:48: cannot use true (untyped bool constant) as resolve.ResolverOptions value in argument to resolve.New
./main.go:495:48: too many errors

Also there seem to be several items that have simplified in approach since the tutorial was written. Might be good to show the simplified APIs.