How do I create a directory structure? I ran these commands to make the directory:

mkdir webpack-demo
cd webpack-demo
npm init -y
npm install webpack --save-dev
npm install webpack-cli --save-dev


and then type cd webpack-demo, then if I type ls I get "node_modules"       "package-lock.json" "package.json"

but then when I attempt to follow the next instructions from the webpack basic set up instruction page:

  webpack-demo
 |- package.json
+ |- index.html
+ |- /src
+ |- index.js


I get the following output from terminal:

|- package.json
-bash: syntax error near unexpected token `|'
+ |- index.html
-bash: +: command not found
-bash: -: command not found
+ |- /src
-bash: +: command not found
-bash: +: command not found
+   |- index.js
-bash: +: command not found
-bash: -: command not found


What am I doing wrong?
The instructions use the same formatting for commands you need to enter and for output, which is confusing. Just use mkdir to create any missing directories. 

PS: It seems as if the directory structure within webpack-demo is created automatically by the various commands you run (or are supposed to run), so you may not even need to create additional directories yourself.