I am not sure what I did, but I spent three hours of my life today trying to get the WiFi to work. I did succeed, but in trying to document the steps, I ended up back at square one.
One of the confusing things I am sure is that after making certain changes to the SD card, such as adding the wpa_supplicant.conf, you need to reboot the RP a second time after the change. I am pretty certain I did this, as documented, and it didn't work, but having polished up my "penguin skills" (I love that!) and randomly pushing buttons and reading through dozens of mostly half relevant and out-of-date topics online, I got it to work.
In documenting my changes, I went back to a blank SD card, followed the instructions without my changes first, and it started working. so rather frustratingly now I have no clue what I did to get it to work.
Basically, though, I'll say this...
o Note that by default, the RP tries to work as an AP rather than as a WiFi client which confuses things
o After adding the wpa_supplicant.conf to the SD card from your main computer, don't forget to reboot twice.