crete directories and subdirectories using mkdir code example

Example 1: mkdir subdirectory

mkdir -p htg/{articles,images,note,done}

Example 2: bash how to create directories in all subdirectories

# Example usage:
for dir in */; do mkdir -- "$dir"/{dir1,dir2,dir3}; done
# This creates directories dir1, dir2, and dir3 in all directories 
# found in the current directory.