Removed MarkdownSharp, move to MarkdownDeep complete

Next step is to utilize the features MarkdownDeep brings to the table.

src/DocNet/Docnet.csproj

@@ -53,7 +53,6 @@
     <Compile Include="Config.cs" />
     <Compile Include="Engine.cs" />
     <Compile Include="INavigationElement.cs" />
-    <Compile Include="MarkdownSharp.cs" />
     <Compile Include="NavigatedPath.cs" />
     <Compile Include="NavigationElement.cs" />
     <Compile Include="NavigationLevel.cs" />