renamed class from ParseXmlToMarkdown to MarkdownNodeParserPool
refactored for style cop
* MarkdownNodeParserPool.cs:
* DocToMarkdown.Tests.csproj:
* CMarkdownNodeParser.cs:
* CodeMarkdownNodeParser.cs:
* ListMarkdownNodeParser.cs:
* RemarksMarkdownNodeParser.cs:
* ReturnsMarkdownNodeParser.cs:
* SummaryMarkdownNodeParser.cs:
* ParamrefMarkdownNodeParser.cs:
* ValueMarkdownNodeParserTest.cs:
* RemarksMarkdownNodeParserTest.cs:
* ParamrefMarkdownNodeParserTest.cs:
* TypeparamrefMarkdownNodeParserTest.cs: renamed class

* DocToMarkdown.csproj: renamed class