block.md

## block

<!-- UTSCOMJSON.block.description -->

<!-- UTSCOMJSON.block.compatibility -->

<!-- UTSCOMJSON.block.attribute -->

<!-- UTSCOMJSON.block.event -->

<!-- UTSCOMJSON.block.component_type -->

<!-- UTSCOMJSON.block.children -->

<!-- UTSCOMJSON.block.example -->

<!-- UTSCOMJSON.block.reference -->