Fork & clone this repo, make sure you have Clojure installed, then run:
clj -M:nextjournal/clerk nextjournal.clerk/serve! --watch-paths src --port 7878 --browseThis will start the Clerk webserver on port 7878 and watch the src/
directory for changes and open Clerk in your browser.
Open one of the files there, make a change and save it. You should then see these changes reflected in the browser.