Renamed `.env.local.default` to `.env.local.example`

[AlexSkrypnyk]

The purpose of this file is to provide example values for a .env.local file that can be used locally by a developer. A consumer project may put more variables and values into this file as needed.

There were some questions raised around .env.local.default vs .env.local.example as default means some sort of "default values" and that this file is being read by the stack (but it is not in reality).

The proposal is to rename .env.local.default to .env.local.example for clarity.

[richardgaunt]

Yes I agree, This does improve the communication of the purpose of the file, I think I had become blinded to its ambiguity with use.