comark/table/empty-block · Give every ::table a file or a table to show

A ::table shows a file, a Markdown table, or one csv, tsv, or json fence. Anything else inside it, such as a paragraph, isn't data, so the block renders nothing.

Incorrect

::table
Mill pond, 14 ducks. Castle moat, 3 ducks.
::

lint-comark example.mdexample.md:1:1 comark/table/empty-block::table 1 has nothing to show.Give it src="data.csv", or put one Markdown table or one csv, tsv, or json fence inside it.✖ 1 problem

Correct

::table
```csv
pond,ducks
Mill pond,14
Castle moat,3
```
::

lint-comark example.md✔ No problems