Published pipeline configuration schema is not complete

[Casper Rademaker]

Hello there,

In our pipelines we validate `bitbucket-pipelines.yml` against the official schema published at api.bitbucket.org/schemas/pipelines-configuration

However, this simple example below which imports and runs a pipeline from another repo which exports it fails on validation

```

options:

  max-time: 3 

clone:

  depth: 1 

pipelines:

  pull-requests:

    "**":

      import: bitbucket-pipeline-templates:main:generic-pr-pipeline
```

Due to:

```

jsonschema.exceptions.ValidationError: {'import': 'bitbucket-pipeline-templates:main:generic-pr-pipeline'} is not of type 'array'

Failed validating 'type' in schema['properties']['pipelines']['properties']['pull-requests']['additionalProperties']:

{'description': 'List of steps, stages and parallel groups of the '

'pipeline.',

'items': {'oneOf': [{'$ref': '#/components/schemas/step_item'},

{'$ref': '#/components/schemas/parallel_item'},

{'$ref': '#/components/schemas/stage_item'},

{'$ref': '#/components/schemas/final_item'}]},

'minItems': 1,

'title': 'Pipeline Items',

'type': 'array'}

On instance['pipelines']['pull-requests']['**']:

{'import': 'bitbucket-pipeline-templates:main:generic-pr-pipeline'}

```

Although this type of import is perfectly valid and works without issues, and is also documented at Share Pipelines Configurations | Bitbucket Cloud | Atlassian Support

It seems the published schema is not complete. Can this be fixed?

Thank you in advance,

Best regards,

Casper Rademaker