In brief, it looks for the adf files you have in a given directory and creates a config file for each one. It copes with games having multiple floppy disks, provided that their file name is exactly the same except the floppy disk number.
Using this script has allowed me to populate the Amiga tab in Retropie with all my amiga games that I can launch directly from the menu. However, I’m still finding myself using the keyboard and mouse. Most of the games in my collection (even those that are legal and approved by the game authors) have “crack” screens that require a mouse-button press to escape. Moreover, to exit a game I have to press Ctrl on the keyboard. Perhaps there is a way to map keys and mouse to the joypad in uae4arm that I’m not aware of? Anyways, I have a mini bluetooth keyboard and mouse that I use for this purpose. It was about £20 from Amazon.