Run make run-local to run the site through Docker.
This means you need Docker, but you don't need to worry about Ruby.
Open a browser to http://localhost:22030 (you can remember the port because of the 2030 Bike Plan).
Otherwise, this is a pretty normal Jekyll site- new blog posts in _posts, etc.
There is a _data/buses.yml file which contains the data that drives bike bus mini-sites
and the 'find your bike bus' list.
Check out that file to see the supported fields.
Each bus gets a site at /<slug>. So the Alameda Bike Bus site is at /alameda.
The code for this is in _plugins/bus_site_generator.rb.
This site originally used the Aditu theme. It's been customized heavily but referring to the original can be helpful.
Its docs are in the aditu-jekyll-theme-v1.2 folder.
Check out a demo.