(Help) Keybind Question

First, **thank you!** I love this plugin!

### Question:
Most of the time, when I want to create a fold, I use `3zF`,
It creates an opening, a blank line for insert, and a closing:
```vim
" test ........ {{{1

" ............. {{{1
```
How would I create a mapping for this, for example with `<Leader>f` ?

Thank you again! great improvement on `origami`!