^ He's quite right.
A Teensy is a general purpose development board. It's down to you to program it to run a keyboard, it won't do it automatically out of the wrapper. Fortunately, there's a handful of firmwares available for you to try. But when driving your own matrix: you're always the one to choose which pins are rows and columns, because every matrix is different.
Here's the Teensy 2 pinout:
The inner labels—PB0 PF0 etc.—are the relevant ones. All the pins starting with P are programmable. Connect each of your rows and columns to *one* of those and then you can define them in the code, and you should be up and running.
I see your diodes. Good move: you've got NKRO that way. Those do mean there's a "right" way and a "wrong" way to drive your matrix. If you have no luck on the first try: swap your columns and rows over in code and it should work. Diodes only let electricity flow through one way, so driving them backwards doesn't work.
(Technically, you drive a matrix by "strobes" and read out the state via "senses". Those are the things to swap if your diodes block you. Soarer's controller defines this explicitly, I've not tried other controllers.)
