This documentation gives a description of how the bats tests are
structured, as well as giving several examples of common test patterns.

Clarified the test naming by including the full first line pattern
that includes the name.

For testing two conditions in the same test, it is reasonable to
follow the existing test patterns and run `helm template` each time.
When testing more conditions, it starts to make sense to separate
the rendering of the yaml from the condition finding and testing.
This commit adds a note to that effect.