Reducing secrets.json credential overlap or confusion

[ccharlton]

I noticed while adding the Diffy Visual Regression Quicksilver script, that username is quite generic. Now, I know for myself, I can change that username secret key in the PHP file to something like diffy_username but I'm not sure if others get that. So, if the key username is used for all script examples, do you think any customers will take pause because they already may have that key used in their secrets file (and not realize it's trivial to update the key accessed in secrets.json)?