added docs strings

docforge/nav/__init__.py

@@ -1,3 +1,19 @@
+"""
+# Navigation Layer
+
+The `docforge.nav` package manages the mapping between the logical documentation
+structure and the physical files on disk.
+
+## Workflow
+
+1.  **Spec Definition**: Users define navigation intent in `docforge.nav.yml`.
+2.  **Resolution**: `resolve_nav` matches patterns in the spec to generated `.md` files.
+3.  **Emission**: `MkDocsNavEmitter` produces the final YAML structure for `mkdocs.yml`.
+
+This abstraction allows doc-forge to support complex grouping and ordering
+independently of the source code's physical layout.
+"""
+
 from .spec import NavSpec, load_nav_spec
 from .resolver import ResolvedNav, resolve_nav
 from .mkdocs import MkDocsNavEmitter