Add Spectre.Cli to Spectre.Console

* Renames Spectre.Cli to Spectre.Console.Cli.
* Now uses Verify with Spectre.Console.Cli tests.
* Removes some duplicate definitions.

Closes #168

examples/Console/Charts/Program.cs

@@ -0,0 +1,21 @@
+using Spectre.Console;
+
+namespace InfoExample
+{
+    public static class Program
+    {
+        public static void Main()
+        {
+            var chart = new BarChart()
+                .Width(60)
+                .Label("[green bold underline]Number of fruits[/]")
+                .CenterLabel()
+                .AddItem("Apple", 12, Color.Yellow)
+                .AddItem("Orange", 54, Color.Green)
+                .AddItem("Banana", 33, Color.Red);
+
+            AnsiConsole.WriteLine();
+            AnsiConsole.Render(chart);
+        }
+    }
+}