Add toc navigation

[studeyang]

I suggest adding directory navigation to the left side of the text. It's not easy to read without directory navigation.

[godalming123]

are you thinking of a sidebar that could be turned on or off in the config.yaml and would allow you to navagate the file tree like in https://flutter.dev/docs where there is a left sidebar for navigating posts I would be happy to try and make that

[rr-bill-keenan]

The menu as on flutter would be great

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[godalming123]

This issue isn't stale! Actually let a human think about it it's a genuinely useful thing. That should be kept around as a testimony to this repo not being maintened.

[fabiomolinar]

I agree a sidebar menu would be a nice feature.

[williamfgc]

It would be nice to have as an option.