Due to the CMMN tutorial being heavily based on XML and manual editing, it relied on highlighting of entire lines of code. Basically like a diff. This was lost when we migrated the docs to hugo. The tutorial text assumes that the code is highlighted, so certain passages are hard to understand without it (for example here: https://docs.camunda.org/get-started/cmmn11/create-case/).
If I am not mistaken, we use prism.js for code highlighting. There is a plugin for prism.js to highlight individual lines of code: http://prismjs.com/plugins/line-highlight/ We should use that and fix the CMMN tutorial.