Netlify CMS is an open source content management system that we use to edit content on the brochure site. Netlify configuration options are in the admin/config.yml file. To develop and make changes to the CMS, or to edit content locally, first comment out the first backend block and then uncomment the second backend block that contains proxy_url. Then, change the branch name to the name of the branch that you are developing on.
After the changes in admin/config.yml are saved and the site is served locally, run
npx netlify-cms-proxy-server
You can then view the CMS in your browser at http://localhost:4000/admin.