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/Rules/Program.cs

@@ -0,0 +1,43 @@
+using Spectre.Console;
+
+namespace EmojiExample
+{
+    public static class Program
+    {
+        public static void Main(string[] args)
+        {
+            // No title
+            Render(
+                new Rule()
+                    .RuleStyle(Style.Parse("yellow"))
+                    .AsciiBorder()
+                    .LeftAligned());
+
+            // Left aligned title
+            Render(
+                new Rule("[blue]Left aligned[/]")
+                    .RuleStyle(Style.Parse("red"))
+                    .DoubleBorder()
+                    .LeftAligned());
+
+            // Centered title
+            Render(
+                new Rule("[green]Centered[/]")
+                    .RuleStyle(Style.Parse("green"))
+                    .HeavyBorder()
+                    .Centered());
+
+            // Right aligned title
+            Render(
+                new Rule("[red]Right aligned[/]")
+                    .RuleStyle(Style.Parse("blue"))
+                    .RightAligned());
+        }
+
+        private static void Render(Rule rule)
+        {
+            AnsiConsole.Render(rule);
+            AnsiConsole.WriteLine();
+        }
+    }
+}