added examples for "Parameter" rules

[pmagyar]

Description of changes:

Hello,
i have noticed, that there are no examples, how to check the existence of Parameters and there configuration.
It is usefull if you have multiple templates and you want to have in every template the same parameters. (e.g. tagging or name schema)

Hope that will help someone.

Best regards,

Patrick

Test output:

python3-virtualenv ~/git_other/cloudformation-guard/guard-examples/parameter-schemas on  parameter_schema ✓ ❯ cfn-guard test -r check-default-parameters.guard -t check-default-parameters-tests.yaml
Test Case #1
  PASS Rules:
    assert_default_parameter_configuration: Expected = SKIP
    assert_default_parameters_exists: Expected = SKIP
    assert_ConstraintDescription: Expected = SKIP

Test Case #2
  PASS Rules:
    assert_ConstraintDescription: Expected = SKIP
    assert_default_parameters_exists: Expected = PASS
    assert_default_parameter_configuration: Expected = FAIL

Test Case #3
  PASS Rules:
    assert_default_parameters_exists: Expected = FAIL
    assert_default_parameter_configuration: Expected = SKIP
    assert_ConstraintDescription: Expected = SKIP

Test Case #4
  PASS Rules:
    assert_ConstraintDescription: Expected = PASS
    assert_default_parameters_exists: Expected = PASS
    assert_default_parameter_configuration: Expected = PASS

Test Case #5
  PASS Rules:
    assert_default_parameters_exists: Expected = PASS
    assert_default_parameter_configuration: Expected = FAIL
    assert_ConstraintDescription: Expected = FAIL

---

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[pmagyar]

Hey,

i have pushed fixes for my typos. Please review/approve again :)
Thanks.

Best regards,

Patrick