feat(docs): migrate bs docs

blocksuite/docs-site/components/blocks/image-block.md

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+# Image Block
+
+This is a block used to display image content. It supports scaling in both the [page editor](../editors/page-editor) and the [edgeless editor](../editors/edgeless-editor), as well as an optional `caption`.
+
+## Reference
+
+- [`ImageBlockSchema`](/api/@blocksuite/blocks/variables/ImageBlockSchema.html)
+- [`ImageBlockService`](/api/@blocksuite/blocks/classes/ImageBlockService.html)