docs: add documentation index linking all project docs

README.md

@@ -4,6 +4,13 @@
 
 It provides an interactive interface for exploring directories with the keyboard and returns the selected path at the end of the session so shell wrappers can change the current shell directory.
 
+
+## Documentation
+
+See the documentation index:
+
+docs/index.md
+
 ## Features
 
 - Interactive terminal directory browser