To set up middleman locally on Fedora:
dnf install ruby rubygems rubygem-bundler rubygem-json
In the git checkout, do a bundle install. This installs all
the needed modules in their appropriate vesions.
Add the middleman binary location (probably ~/bin) to $PATH.
To run a local web server to test the site:
bundle exec middleman server
Edit the haml/scss files and commit your changes, pushing to origin/source.
You must be on the source branch to deploy.
To deploy your changes:
rm -rf build
bundle exec middleman build
bundle exec middleman deploy
This will push the site from ./build into origin/master branch. The flatpak sysadmins then have to update the live site.