Add a link example using the "path" reference prefix to the Syntax documentation

Updates texts from the link documentation. The text can be found here:

• In the product @ xwiki/bin/view/XWiki/XWikiSyntax?xpage=print#HLinks
• On xwiki.org @ http://platform.xwiki.org/xwiki/bin/view/Main/XWikiSyntax#HLinks

When I was searching for the syntax 2.1 I found that "The full format of a link is [label>>] (resource) [||parameters]"

1 - It appears that one example which might be wrong is url:http://domain.com/path||queryString="mydata1=5&mydata2=Hello"

2 - Searching for path: examples, I didn't found any and it appears that the result was [[label>>path:${xwiki.getURL('space.page', 'mode','parameter')}]] which is not respecting the syntax explained before it.

I was confused by the URL example. It needs an example for path: which is commonly used.