The in game controller 'customize' option froze up my computer. I realize this is a known bug. I'm writing this post to make it a little easier for whoever may be searching online to figure out how to make the changes to the config.txt file.

The //joystick paragraph that I was left with after some tinkering:

//joystick
control_dat4 0 2 0 4 0 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 1 4 1 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 2 4 2 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 3 4 3 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 4 3 7 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 5 3 4 0 3 5 0 0 0 0 0 0 0
control_dat4 0 2 6 3 2 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 7 3 1 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 8 3 3 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 9 3 0 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 10 3 6 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 11 4 8 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 12 4 9 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 13 0 0 0 0 0 0 0 0 0 0 0 0
control_dat4 0 2 14 0 0 0 0 0 0 0 0 0 0 0 0

which translates to (line by line):

move left: left-stick left (4 0 0)
move right: left-stick right (4 1 0)
move up: left-stick up (4 2 0)
move down: left-stick down (4 3 0)
shoot: start button (3 7 0) (I used this as 'enter' in menus)
jump: left bumper (3 4 0) and right bumber (3 5 0)
shoot left: x (3 2 0)
shoot right: b (3 1 0)
shoot up: y (3 3 0)
shoot down: a (3 0 0)
menu: back button (3 6 0)
cam up: right-stick up (4 8 0)
cam down: right-stick down (4 9 0)
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Thanks to aurym who posted a different version of this on the blog of this site two years ago.
aurym's post

I wish I would have found zep's post before I figured out that the buttons are represented by groups of 3 numbers and not groups of two. It would have made things a lot easier knowing:
............................
The first 3 numbers on each line you can leave alone:
player index
profile index
button index

The following 12 are 4 triplets -- one for each action. If you only want one button for each action, you could set the last 9 on each row to zero.
............................

I hope this helps someone.
Cheers.