There are npm install commands all over the guide (v7.2) without the --save or --save-dev flags like:

npm install bootstrap react-bootstrap react-icons

These should probably be corrected to include --save/--save-dev in the future?

--save is the default behaviour. Nowadays with bundling tools it no longer matters as much whether you install packages for development or non-dev. For your example I guess it makes sense to install them normally as they are used in your app, however tools like jest or eslint remain in dev as they are only meant for development.

Thanks for the clarification!