Example from readme.md is not working

[lintaba]

Error message: configuration error: package name must be specified

$ go version
go version go1.19.3 darwin/amd64
$ go install github.com/deepmap/oapi-codegen/cmd/oapi-codegen@latest
$ ls
specs.yaml
$ oapi-codegen specs.yaml 
configuration error: package name must be specified
$ oapi-codegen -package packagename specs.yaml >/dev/null
$

a minimal specs.yaml has been attached: specs.txt

I already made a PR to fix this: https://github.com/deepmap/oapi-codegen/pull/861