Moved all Pillar examples under the same dictionary key

Having multiple different examples in the same file was causing
confusion.
Removed Jinja-esque placeholders from example Pillar; added instructions

The structure of this example file was quite confusing. Most of these
values are not required and should be denoted as such. Jinja notiation
to denote re-used Pillar values was also a bad and confusing choice.

Closes #8