Docs: generate api docs for inventory

docs/nix/shell.nix

@@ -3,6 +3,7 @@
   pkgs,
   module-docs,
   clan-cli-docs,
+  inventory-api-docs,
   asciinema-player-js,
   asciinema-player-css,
   roboto,
@@ -19,6 +20,8 @@ pkgs.mkShell {
     mkdir -p ./site/reference/cli
     cp -af ${module-docs}/* ./site/reference/
     cp -af ${clan-cli-docs}/* ./site/reference/cli/
+    cp -af ${inventory-api-docs} ./site/reference/nix-api/inventory.md
+
     chmod +w ./site/reference/*
 
     echo "Generated API documentation in './site/reference/' "