MarkdownParser get original Markdown from MarkdownElement or MarkdownBlock

I'm submitting a...

• Feature request (UserVoice request: )

Current behavior

MarkdownBlock returns only sanitized text from the orignial markdown or .net default behaivour on calling ToString().

Expected behavior

MarkdownBlock should have a property similar to public String OrignalMarkdown { get; } which returns the original markdown passed to ParagraphBlock.Parse.

Minimal reproduction of the problem with instructions

Parse a markdown document and call .ToString() on any MarkdownBlock.

MarkdownDocument markdownDocument = new MarkdownDocument();
markdownDocument.Parse("## I'm a Header\r\nI'm a simple Text");

foreach(var item in markdownDocument.Blocks)
{
    //returns only sanitzed text
    Debug.WriteLine(item.ToString());
}

Environment

Nuget Package(s): 

Package Version(s): 

Windows 10 Build Number:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [ x ] October 2018 Update (17763)
- [ ] Insider Build (build number: )

App min and target version:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [ x ] October 2018 Update (17763)
- [ ] Insider Build (xxxxx)

Device form factor:
- [ x ] Desktop
- [ ] Mobile
- [ ] Xbox
- [ ] Surface Hub
- [ ] IoT

Visual Studio 
- [ x ] 2017 (version: 15.9.4)
- [ ] 2017 Preview (version: )