Add documentation for Breakdown Chart (#1000)

* Begin breakdown chart documentation
* Fix generator build failure
* Add in breakdown chart graphics
* Add breakdown chart documentation and move cast files

docs/input/widgets/barchart.md

@@ -6,14 +6,13 @@ Highlights:
     - Labels
     - Use your own data with a converter.
 Reference: T:Spectre.Console.BarChart
-    
+
 ---
 
 Use `BarChart` to render bar charts to the console.
 
 <?# AsciiCast cast="bar-chart" /?>
 
-
 ## Usage
 
 ### Basic usage

docs/input/widgets/breakdownchart.md

@@ -0,0 +1,134 @@
+Title: Breakdown Chart
+Order: 25
+Description: "Use **BreakdownChart** to render breakdown charts to the console."
+Highlights:
+    - Custom colors
+    - Labels
+    - Use your own data with a converter.
+Reference: T:Spectre.Console.BreakdownChart
+
+---
+
+Use `BreakdownChart` to render breakdown charts to the console.
+
+<?# AsciiCast cast="breakdown-chart" /?>
+
+## Usage
+
+### Basic usage
+
+```csharp
+AnsiConsole.Write(new BreakdownChart()
+    .Width(60)
+    // Add item is in the order of label, value, then color.
+    .AddItem("SCSS", 80, Color.Red)
+    .AddItem("HTML", 28.3, Color.Blue)
+    .AddItem("C#", 22.6, Color.Green)
+    .AddItem("JavaScript", 6, Color.Yellow)
+    .AddItem("Ruby", 6, Color.LightGreen)
+    .AddItem("Shell", 0.1, Color.Aqua));
+```
+
+### Additional Styling
+
+```csharp
+// Render chart at full width of console.
+AnsiConsole.Write(new BreakdownChart()
+    .FullSize()
+    .AddItem("SCSS", 80, Color.Red)
+    .AddItem("HTML", 28.3, Color.Blue)
+    .AddItem("C#", 22.6, Color.Green)
+    .AddItem("JavaScript", 6, Color.Yellow)
+    .AddItem("Ruby", 6, Color.LightGreen)
+    .AddItem("Shell", 0.1, Color.Aqua));
+```
+
+```csharp
+// Show percentage signs after the values in the chart.
+AnsiConsole.Write(new BreakdownChart()
+    .ShowPercentage()
+    .AddItem("SCSS", 80, Color.Red)
+    .AddItem("HTML", 28.3, Color.Blue)
+    .AddItem("C#", 22.6, Color.Green)
+    .AddItem("JavaScript", 6, Color.Yellow)
+    .AddItem("Ruby", 6, Color.LightGreen)
+    .AddItem("Shell", 0.1, Color.Aqua));
+```
+
+```csharp
+// Hide tags displaying in the chart altogether.
+AnsiConsole.Write(new BreakdownChart()
+    .HideTag()
+    .AddItem("SCSS", 80, Color.Red)
+    .AddItem("HTML", 28.3, Color.Blue)
+    .AddItem("C#", 22.6, Color.Green)
+    .AddItem("JavaScript", 6, Color.Yellow)
+    .AddItem("Ruby", 6, Color.LightGreen)
+    .AddItem("Shell", 0.1, Color.Aqua));
+```
+
+```csharp
+// Hide the values next to the tag from displaying in the chart.
+AnsiConsole.Write(new BreakdownChart()
+    .HideTagValues()
+    .AddItem("SCSS", 80, Color.Red)
+    .AddItem("HTML", 28.3, Color.Blue)
+    .AddItem("C#", 22.6, Color.Green)
+    .AddItem("JavaScript", 6, Color.Yellow)
+    .AddItem("Ruby", 6, Color.LightGreen)
+    .AddItem("Shell", 0.1, Color.Aqua));
+```
+
+### Additional Functionality
+
+#### Add items with converter
+
+```csharp
+// Create a list of fruits with their colors
+var items = new List<(string Label, double Value, Color color)>
+{
+    ("Apple", 12, Color.Green),
+    ("Orange", 54, Color.Orange1),
+    ("Banana", 33, Color.Yellow),
+};
+
+// Render the chart
+AnsiConsole.Write(new BreakdownChart()
+    .FullSize()
+    .ShowPercentage()
+    .AddItems(items, (item) => new BreakdownChartItem(
+        item.Label, item.Value, item.color)));
+```
+
+#### Add items implementing IBreakdownChartItem
+
+```csharp
+// Declare Fruit that implements IBreakdownChartItem
+public sealed class Fruit : IBreakdownChartItem
+{
+    public string Label { get; set; }
+    public double Value { get; set; }
+    public Color Color { get; set; }
+
+    public Fruit(string label, double value, Color color)
+    {
+        Label = label;
+        Value = value;
+        Color = color;
+    }
+}
+
+// Create a list of fruits
+var items = new List<Fruit>
+{
+    new Fruit("Apple", 12, Color.Green),
+    new Fruit("Orange", 54, Color.Orange1),
+    new Fruit("Banana", 33, Color.Yellow),
+}
+
+// Render chart
+AnsiConsole.Write(new BreakdownChart()
+.Width(60)
+.AddItem(new Fruit("Mango", 3, Color.Orange4))
+.AddItems(items));
+```