Add the meta.maintainers and meta.doc options in the unit module

nix/fg42/lib.nix

@@ -16,6 +16,8 @@
 { pkgs, ... }:
 final: prev:
 rec {
+  maintainers = import ../../maintainers.nix;
+
   /*
     Create a value to be accessable on the Elisp side as a variable.
   */

nix/modules/unit/README.md

@@ -0,0 +1 @@
+# Unit Module

nix/modules/unit/default.nix

@@ -34,9 +34,60 @@ let
 
     src = ./.;
   };
+
+  maintainer = mkOptionType {
+    name = "maintainer";
+    check = email: elem email (attrValues lib.maintainers);
+    merge = loc: defs: listToAttrs (singleton (nameValuePair (last defs).file (last defs).value));
+  };
+
+  listOfMaintainers = types.listOf maintainer // {
+    # Returns list of
+    #   { "module-file" = [
+    #        "maintainer1 <first@nixos.org>"
+    #        "maintainer2 <second@nixos.org>" ];
+    #   }
+    merge = loc: defs:
+      zipAttrs
+        (flatten (imap1
+          (n: def: imap1
+            (m: def':
+              maintainer.merge (loc ++ [ "[${toString n}-${toString m}]" ])
+                [{ inherit (def) file; value = def'; }])
+            def.value)
+          defs));
+  };
+  docFile = types.path // {
+    # Returns tuples of
+    #   { file = "module location"; value = <path/to/doc.xml>; }
+    merge = loc: defs: defs;
+  };
+
 in
 {
   options = {
+    meta = {
+      maintainers = mkOption {
+        type = listOfMaintainers;
+        internal = true;
+        default = [ ];
+        example = literalExpression ''[ lib.maintainers.all ]'';
+        description = lib.mdDoc ''
+          List of maintainers of each module.  This option should be defined at
+          most once per module.
+        '';
+      };
+
+      doc = mkOption {
+        type = docFile;
+        internal = true;
+        example = "./meta.chapter.md";
+        description = lib.mdDoc ''
+          Documentation prologue for the set of options of each module.  This
+          option should be defined at most once per module.
+        '';
+      };
+    };
     fg42.version = mkOption {
       type = types.str;
       visible = true;
@@ -197,6 +248,10 @@ in
       '')
     ];
 
+    meta = {
+      maintainers = [ maintainers.lxsameer ];
+      doc = ./README.md;
+    };
   };
 
 }