Deleted the incorrect example of inserting URLs under header Personalized Links, added another header Escaping Links with correct example.
Deleted the incorrect example of inserting URLs under header Personalized Links, added another header Escaping Links with correct example.

tjtate/sparkpost-api-documentation,tjtate/sparkpost-api-documentation,SparkPost/sparkpost-api-documentation,SparkPost/sparkpost-api-documentation,tjtate/sparkpost-api-documentation,SparkPost/sparkpost-api-documentation