Just updated the Fight-Or-Flight guide

Just a note to say that I updated the guide to the Fight-Or-Flight response to add some new information from a great book that I recommend reading, Why Zebras Don't Get Ulcers: An Updated Guide to Stress, Stress-Related Diseases, and Coping by Dr. Robert M. Sapolsky. This book was recommended to me by my therapist and I've had a hard time putting it down, it's a great read with some comedy thrown in, and thoroughly explains the body's reaction to stress and the effects of prolonged exposure to stress.