In the [README.md](https://github.com/oreillymedia/asciidoctor-htmlbook/commit/330dd7f2dce49432e41617c7efc04b9721781553#diff-04c6e90faac2675aa89e2176d2eec7d8R7), there is the line: > `htmlbook-autogen` - a set of templates that can only be used with the `orm_asciidoctor` gem. This provides some autogeneration abilities. Is the reference to `orm_asciidoctor` out-of-date? I [can't find such a gem](https://rubygems.org/search?utf8=%E2%9C%93&query=orm_asciidoctor).