Non-terminal symbol `ChildXmlTree`

A child XML tree denotes the contents on the XML tree being built for a child CST node.

Defining rules for nonterminal symbol ChildXmlTree:

`ChildXmlTree`		`SpecialForm`
		`POSITION` `XmlPath_opt`

Occurrences of symbol ChildXmlTree in body of other rules:

`TextRef`		`ChildXmlTree` `AttributeName_opt`
`XmlChildSpec`		`WrapperPath_opt` `ChildXmlTree`

Non-terminal symbol ChildXmlTree