This command transpile the source files and start a development webserver. Any change you make to the source TypeScript, HTML and SCSS files will automatically be recompiled. Go to http://localhost:4000/index.html to view your changes.
Each theme is located in a subdirectory of `src/stylesheets/themes`. Themes must have an `index.scss` and `utterances.scss` files. These are the entrypoint stylesheets for the utterances homepage and utterances widget respectively. *Todo: more instructions*