docs: remove non existent keybind (#2080)

packages/web/src/content/docs/docs/keybinds.mdx

@@ -20,7 +20,6 @@ opencode has a list of keybinds that you can customize through the opencode conf
     "session_export": "<leader>x",
     "session_new": "<leader>n",
     "session_list": "<leader>l",
-    "session_navigation": "<leader>g",
     "session_share": "<leader>s",
     "session_unshare": "none",
     "session_interrupt": "esc",