Add 'other' text input to checkbox collection

[Luca Rossi]

Hi all, 

I spent a bit trying to find the best solution for this, how would you add a text field for an 'other' option in a checkbox collection group?

I am manually adding the extra text field after the collection field, but I would like it to be inside the last checkbox div so that I can place the box and the input field next to each other. 

Thanks in advance.