MDL-66109 behat: Fix Example usage in feature files

MDL-66109 behat: Fix Example usage in feature files

The gherkin-lint package now understands the use of "Examples" and
requries that their indentation be correct and consistent.

This change sets the indentatation for these to:

    "Examples": 4,
    "example": 6,

This is in-line with the examples given in the offical Cucumber/Gherkin
documentation at
https://cucumber.io/docs/gherkin/reference/#scenario-outline whereby the
Examples and individual rows of the Examples table are children of the
Scenario outline.

This is contrary to the default for Gherkin-lint which places them as
top-level nodes with an indentatio of 0, and 2 respectively.