where u find em ?

I guess I am about 2 weeks late with my reply, but will post anyways, in case someone else is wondering too:

1. open up your blizzard launcher.

2. select heroes of the storm (dont start the game just click once)

3. top left corner somewhere is where "heroes of the storm" should be written. Below that you can see a gear and the word "options". --> click it.

4. First option says "patch notes"

enjoy