> So this would be called a configuration file (or 'input file' since it's sort of data + configuration) rather than a programming language or configuration language.

The readme calls it an input file. ("declarative input in the form of a markdown file"). It never claims to be a DSL or a programming language, just calls the input declarative. "Declarative" is a bit of cop-out, but I want a way to showcase that it is different from a standard YAML config that would only take the variables part - it defines the end state, and is just an alternate representation of the final PDF in a way.

Wikipedia defines declarative as:

>a style of building the structure and elements of computer programs—that expresses the logic of a computation without describing its control flow.

I'm just using it in a sense closer to configuration management systems (so declarative config) - similar to how something like Ansible would call its configuration YAML files (`apt: [a,b,c]` is a declarative config).