Support the new block types `table` and `table_row`

[bgmort]

I'd like to make use of the new Notion simple tables with notablog. Somebody already filed the request here: https://github.com/dragonman225/notablog/issues/26

Trying to do so produces these messages in the console:

Unsupported block type: table
Unsupported block type: table_row

Support for these types is needed in order to support them in notablog.