Active Link dosen't work

10

I installed the menus as suggested by Rick and they work flawlessly. If I click on the link Handbook in the Navbar, /handbook/toc will appear. But if I call in the browser /handboook, then the index page appears. But when I /handbook calls, I want the content of Siete toc.md to be displayed. I renamed toc.md to index.md and _index.md. Unfortunately, the result is always a list page. Maybe I should create a folder /layout /handbook/ index.html? The content of index.html is that of single.html.