How do I add new snippets?

Normally you can insert a new snippet following a text snippet by typing the Return key. Within a code snippet, you need to type Primary+Return (where Primary is either the Command or Control key, depending on your platform).

Try it here.

"Also try to add a new code snippet here."
  

You can also add any kind of snippet below a given one by clicking on the + button at the bottom of the snippet. Try to add a Pharo (code) snippet below this one.