filePickF :: F String (InputMsg String)
filePickF
provides a file selection dialog. It consists of three fields:
directory string input field, a file list, and a file string input field.
A file is normally selected by clicking on it in the file list, but it is
also possible to select a directory by entering its path in the directory
input field, or to enter a file name directly in the file input field.
startupF ["/usr/bin"] filePickF