pandoc/test/command/7400.md

```
% pandoc -t native -s
---
# Comment only
...
^D
Pandoc Meta { unMeta = fromList [] } []
```
Fix regression with comment-only YAML metadata blocks. Closes #7400. 2021-06-22 18:55:50 +02:00			```
			`% pandoc -t native -s`
			`---`
			`# Comment only`
			`...`
			`^D`
Switch from pretty-simple to pretty-show for native output. Update tests. Reason: it turns out that the native output generated by pretty-simple isn't always readable by the native reader. According to https://github.com/cdepillabout/pretty-simple/issues/99 it is not a design goal of the library that the rendered values be readable using 'read'. This makes it unsuitable for our purposes. pretty-show is a bit slower and it uses 4-space indents (non-configurable), but it doesn't have this serious drawback. 2021-09-29 06:17:53 +02:00			`Pandoc Meta { unMeta = fromList [] } []`
Fix regression with comment-only YAML metadata blocks. Closes #7400. 2021-06-22 18:55:50 +02:00			```