add block example

[MarieComet]

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Note

Low Risk
Low risk: this only adds a Gutenberg example configuration to block.json for editor preview, without changing runtime logic or data handling.

Overview
Adds a predefined Gutenberg block example for blockparty/accordion, including nested accordion-item/summary/panel inner blocks and sample paragraph content, with the first item configured to be open by default for preview purposes.

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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Non-existent attribute referenced in block example

Low Severity

The openByDefault attribute is specified on the blockparty/accordion-item inner block in the example, but this attribute doesn't exist as a registered attribute for that block. The item's block.json defines no attributes at all. The open-first-item behavior is controlled solely by the parent's firstItemOpenByDefault attribute (which is already correctly set in the example). The openByDefault attribute will be silently ignored, making it misleading dead configuration.

 

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