I had ESO installed through Steam.
The folder wasn't being found, even when I manually added it.
I tried deleting the .xml file.
What did work for me:
In settings you can select the folder search depth that Minion will use to find the folder.
I moved this up to a depth of 6.
I then clicked force Minion to redetect addOns.
Folder was found.
Hope this helps
Okay the CORRECT path was C:\Users\<username>\Documents\Elder Scrolls Online\live\AddOns\
Notice that path is Documents, not My Documents.
I noticed this was stated before, but when I go into Windows Explorer and navigate to
C:\Users\<username>\ there is a My Documents displayed in there, but not Documents.
Specifically, Windows displays the Documents folder as "My Documents", but the folder name is literally "Documents".
That was my point of error.