Assert minimum `process-compose` version

[srid]

Perhaps as apply option to this:

process-compose-flake/nix/process-compose/default.nix

Lines 14 to 21 in 9344fac

	package = mkOption {
	type = types.package;
	default = pkgs.process-compose;
	defaultText = lib.literalExpression "pkgs.process-compose";
	description = ''
	The process-compose package to bundle up in the command package and flake app.
	'';
	};

---

nixpkgs reference example,

https://github.com/NixOS/nixpkgs/blob/cb276443480ea124714ace4e972e6b3170d797ff/pkgs/applications/science/logic/klee/default.nix#L44

cf. #71