Micro.blog has special Pages that you can add to your blog. Custom themes can get the list of menu item names and their URLs by accessing the site variable site.Menus.main. Many themes use the folllowing in there head/header partial:

{{ with site.Menus.main }}
       {{ range . }}
         <a class="{{ if eq .URL $url }}active{{ end }}" href="{{ .URL }}">
           {{ .Name }}
         </a>
       {{ end }}
{{ end }}