[Proposed Feature] Display the Table of Content for README

[giswqs]

Description of Feature:
It would be useful to display the Table of Content for the README file. This will make it easier to navigate a README file with lengthy content.
https://beta.source.coop/repositories/giswqs/nwi/description/

Like this:
https://geog-414.gishub.org/book/duckdb/11_data_analysis.html

[kbgg]

Thanks for the feature request! We just opened up the source code for the viewers and are welcoming contributions if anyone wants to update the markdown viewer here

[giswqs]

I am trying to learning TypeScript. Hope to contribute when I can.