Error from OOXMLValidator:
```
{
"Description": "The required attribute 'val' is missing.",
"Path": {
"NamespacesDefinitions": [
"xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\""
],
"Namespaces": {
},
"XPath": "/w:document[1]/w:body[1]/w:tbl[1]/w:tr[1]/w:trPr[1]/w:cnfStyle[1]",
"PartUri": "/word/document.xml"
},
"Id": "Sch_MissRequiredAttribute",
"ErrorType": "Schema"
},
```
This is a bitmask where the first bit means 'first row', which is set as
an attribute already.
Signed-off-by: Edwin Török <edwin@etorok.net>
Instead of just "Hello, world", the document now contains
exemplars of most of the styles that have an effect on pandoc
documents.
This makes it easier to see the effect of style changes.
Closes#4175.