Update emoji support

* Add constants for emojis
* Move emoji shortcode rendering to Markup
* Add documentation
* Add example
* Add tests

docs/input/_layout.cshtml

@@ -128,14 +128,28 @@
                                         {
                                             IDocument root = OutputPages["index.html"].First();
                                             <div class="sidebar-nav-item @(Document.IdEquals(root) ? "active" : null)">
-                                                @Html.DocumentLink(root)
+                                                    @if(root.ShowLink())
+                                                    {
+                                                        @Html.DocumentLink(root)
+                                                    }
+                                                    else
+                                                    {
+                                                        @root.GetTitle()
+                                                    } 
                                             </div>
 
                                             @foreach (IDocument document in OutputPages.GetChildrenOf(root).OnlyVisible())
                                             {
                                                 DocumentList<IDocument> documentChildren = OutputPages.GetChildrenOf(document);
                                                 <div class="sidebar-nav-item @(Document.IdEquals(document) ? "active" : null) @(documentChildren.Any() ? "has-children" : null)">
-                                                    @Html.DocumentLink(document)
+                                                    @if(document.ShowLink())
+                                                    {
+                                                        @Html.DocumentLink(document)
+                                                    }
+                                                    else
+                                                    {
+                                                        @document.GetTitle()
+                                                    }                                                   
                                                 </div>
 
                                                 @if (documentChildren.OnlyVisible().Any())

docs/input/appendix/emojis.md

@@ -0,0 +1,38 @@
+Title: Emojis
+Order: 3
+---
+
+Please note that what emojis that can be used is completely up to 
+the operating system and/or terminal you're using, and no guarantees
+can be made of how it will look. Calculating the width of emojis
+is also not an exact science in many ways, so milage might vary when
+used in tables, panels or grids.
+
+To ensure best compatibility, consider only using emojis introduced
+before Unicode 13.0 that belongs in the `Emoji_Presentation` category
+in the official emoji list at 
+https://www.unicode.org/Public/UCD/latest/ucd/emoji/emoji-data.txt
+
+# Usage
+
+```csharp
+// Markup
+AnsiConsole.MarkupLine("Hello :globe_showing_europe_africa:!");
+
+// Constant
+var hello = "Hello " + Emoji.Known.GlobeShowingEuropeAfrica;
+```
+
+# Replacing emojis in text
+
+```csharp
+var phrase = "Mmmm :birthday_cake:";
+var rendered = Emoji.Replace(phrase);
+```
+
+# Emojis
+
+_The images in the table below might not render correctly in your 
+browser for the same reasons mentioned in the `Compatibility` section._
+
+<?# EmojiTable /?>

docs/input/appendix/index.md

@@ -1,3 +1,10 @@
 Title: Appendix
 Order: 10
----
+---
+
+# Sections
+
+* [Styles](xref:styles)
+* [Colors](xref:colors)
+* [Borders](xref:borders)
+* [Emojis](xref:emojis)

docs/input/markup.md

@@ -2,8 +2,7 @@ Title: Markup
 Order: 2
 ---
 
-In `Spectre.Console` there's a class called `Markup` that
-allows you to output rich text to the console.
+The class `Markup` allows you to output rich text to the console.
 
 # Syntax
 
@@ -54,6 +53,16 @@ You can set the background color in markup by prefixing the color with
 [default on blue]World[/]
 ```
 
+# Rendering emojis
+
+To output an emoji as part of markup, you can use emoji shortcodes.
+
+```csharp
+AnsiConsole.MarkupLine("Hello :globe_showing_europe_africa:!");
+```
+
+For a list of emoji, see the [Emojis](xref:styles) appendix section.
+
 # Colors
 
 For a list of colors, see the [Colors](xref:colors) appendix section.