Emojis don't get converted at the start of links

[Flayms]

With the following code

using Markdig;

var markdown = "[:clap: a link :clap:](https://github.com/xoofx/markdig)";

var pipeline = new MarkdownPipelineBuilder()
    .UseEmojiAndSmiley()
    .Build();

var html = Markdown.ToHtml(markdown, pipeline);

I am getting the following output:

<p><a href="https://github.com/xoofx/markdig">:clap: a link 👏</a></p>

I believe the first emoji should be converted as well.

[Scooletz]

This is probably due to:

markdig/src/Markdig/Extensions/Emoji/EmojiParser.cs

Lines 29 to 33 in 391f376

	// Previous char must be a space
	if (!slice.PeekCharExtra(-1).IsWhiteSpaceOrZero())
	{
	return false;
	}

The question is whether it's aligned to the spec that requires a space before an emoji https://github.com/xoofx/markdig/blob/master/src/Markdig.Tests/Specs/EmojiSpecs.md