Create a default exit point for snippets

[smfoote]

Sublime Text provides a default "exit point" for snippets; after the last tab stop, the cursor is moved to the end of the snippet's content. Atom does not appear to have a default exit point for snippets, which means that if you want an exit point in your snippet you have to create it yourself.

Interestingly, the $0 marker that is used in Sublime to override the default exit point does seem to work in Atom.