Table with no columns is no longer a table

this is now just raw text:

```md
|
|
|
```

close https://github.com/markdown-it/markdown-it/issues/724

CHANGELOG.md

@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
+## [12.0.2] - WIP
+### Fixed
+- Three pipes (`|\n|\n|`) are no longer rendered as a table with no columns, #724.
+
+
 ## [12.0.1] - 2020-10-19
 ### Fixed
 - Fix tables inside lists indented with tabs, #721.
@@ -529,6 +534,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Renamed presets folder (configs -> presets).
 
 
+[12.0.2]: https://github.com/markdown-it/markdown-it/compare/12.0.1...12.0.2
 [12.0.1]: https://github.com/markdown-it/markdown-it/compare/12.0.0...12.0.1
 [12.0.0]: https://github.com/markdown-it/markdown-it/compare/11.0.1...12.0.0
 [11.0.1]: https://github.com/markdown-it/markdown-it/compare/11.0.0...11.0.1

lib/rules_block/table.js

@@ -118,7 +118,7 @@ module.exports = function table(state, startLine, endLine, silent) {
   // header row will define an amount of columns in the entire table,
   // and align row should be exactly the same (the rest of the rows can differ)
   columnCount = columns.length;
-  if (columnCount !== aligns.length) { return false; }
+  if (columnCount === 0 || columnCount !== aligns.length) { return false; }
 
   if (silent) { return true; }
 

test/fixtures/markdown-it/tables.txt

@@ -604,6 +604,19 @@ Regression test for #721, table in a list indented with tabs:
 </ul>
 .
 
+
+Table without any columns is not a table, #724
+.
+|
+|
+|
+.
+<p>|
+|
+|</p>
+.
+
+
 GFM 4.10 Tables (extension), Example 198
 .
 | foo | bar |