docs: generate api docs

docs/nix/flake-module.nix

@@ -1,4 +1,4 @@
-{ inputs, ... }:
+{ inputs, self, ... }:
 {
   perSystem =
     {
@@ -7,11 +7,61 @@
       pkgs,
       ...
     }:
+    let
+      # Simply evaluated options (JSON)
+      # { clanCore = «derivation JSON»; clanModules = { ${name} = «derivation JSON» }; }
+      jsonDocs = import ./get-module-docs.nix {
+        inherit (inputs) nixpkgs;
+        inherit pkgs;
+        inherit (self.nixosModules) clanCore;
+        inherit (self) clanModules;
+      };
+
+      clanModulesFileInfo = pkgs.writeText "info.json" (builtins.toJSON jsonDocs.clanModules);
+
+      # Simply evaluated options (JSON)
+      renderOptions =
+        pkgs.runCommand "renderOptions.py"
+          {
+            # TODO: ruff does not splice properly in nativeBuildInputs
+            depsBuildBuild = [ pkgs.ruff ];
+            nativeBuildInputs = [
+              pkgs.python3
+              pkgs.mypy
+            ];
+          }
+          ''
+            install ${./scripts/renderOptions.py} $out
+            patchShebangs --build $out
+
+            ruff format --check --diff $out
+            ruff --line-length 88 $out
+            mypy --strict $out
+          '';
+
+      module-docs = pkgs.runCommand "rendered" { nativeBuildInputs = [ pkgs.python3 ]; } ''
+        export CLAN_CORE=${jsonDocs.clanCore}/share/doc/nixos/options.json 
+        # A file that contains the links to all clanModule docs
+        export CLAN_MODULES=${clanModulesFileInfo}
+
+        mkdir $out
+
+        # The python script will place mkDocs files in the output directory
+        python3 ${renderOptions}
+      '';
+    in
     {
-      devShells.docs = pkgs.callPackage ./shell.nix { inherit (self'.packages) docs; };
+      devShells.docs = pkgs.callPackage ./shell.nix {
+        inherit (self'.packages) docs;
+        inherit module-docs;
+      };
       packages = {
-        docs = pkgs.python3.pkgs.callPackage ./default.nix { inherit (inputs) nixpkgs; };
+        docs = pkgs.python3.pkgs.callPackage ./default.nix {
+          inherit (inputs) nixpkgs;
+          inherit module-docs;
+        };
         deploy-docs = pkgs.callPackage ./deploy-docs.nix { inherit (config.packages) docs; };
+        inherit module-docs;
       };
     };
 }