feat: add --api OpenAPI build mode with docs/api scheme and lib-prefixed nav

docforge/cli/mkdocs_utils.pyi

@@ -1,3 +1,4 @@
+from collections.abc import Iterable
 from pathlib import Path
 
 def generate_sources(
@@ -5,9 +6,17 @@ def generate_sources(
     docs_dir: Path,
     project_name: str | None = None,
     module_is_source: bool | None = None,
+    readme_dir: Path | None = None,
 ) -> None: ...
 def generate_config(
-    docs_dir: Path, nav_file: Path, template: Path | None, out: Path, site_name: str
+    docs_dir: Path,
+    nav_file: Path,
+    template: Path | None,
+    out: Path,
+    site_name: str,
+    modes: Iterable[str] | None = None,
+    site_description: str | None = None,
+    site_author: str | None = None,
 ) -> None: ...
 def build(mkdocs_yml: Path) -> None: ...
 def serve(mkdocs_yml: Path) -> None: ...