I'm new to this list and thinking about a german translation of the material.
Looking through command_memento I see some inconsistencies:
"Create nested directories:
mkdir -p dir1 dir2"
-> Seems to missing a slash, as my bash creates two directories dir1 and dir2
in the current working dir.
"List all “regular” files (no starting with .) in the current directory:"
-> I would suggest "not" instead of "no" (?).
"Add read permissions to users in the file group:
chmod g+r file"
-> Perhaps a better wording: "Add read permissions for the group to which file
"Find all the .pdf files in dir and run a command on each:"
-> This is recursive as in the example above it.