Merge Atmos specific and terraform/helmfile help documentation @samtholiya (#857)

what

• Merge Atmos specific and terraform/helmfile help documentation

why

• Show the native terraform/helmfile commands and Atmos-specific terraform/helmfile commands

Separate Test Fixtures from Examples @milldr (#918)

what

• Move examples/tests to tests/fixtures

why

• Examples are intended to be just that, examples. We should not be including test usages with the examples