delist graph notation until gram is released

Author: akollegger

Diff for: astro.config.mjs

@@ -112,10 +112,8 @@ export default defineConfig({
       }, {
         label: 'Glossary',
         link: '/appendices/glossary'
-      }, {
-        label: 'Graph Notation',
-        link: '/appendices/notation'
-      }]
+      }
+    ]
     }],
     components: {
       Footer: './src/components/GrFooter.astro'