Easier editing of multiline comments

Thanks for creating the package!

It would be awesome if in the following case:

``` lua
-- Makes something important<CURSOR HERE>
function foo()
   ...
end
```

the editor would automatically comment the next line if I press <kbd>Enter</kbd>:

``` lua
-- Makes something important
-- <CURSOR HERE>
function foo()
   ...
end
```

This would hugely facilitate inserting multiline comments.
