Currently when `globalCssPath` is omitted from `canvas.config.json`, the fallback value used by the CLI and Workbench is `src/components/global.css`. This is a leftover from an early CLI implementation. Keeping that file as `src/global.css` by default feels more idiomatic, and it's also the path we chose with `acquia/nebula` and `balintbrews/canvas-starter`.