Add support for aligning tables

examples/Colors/Program.cs

@@ -1,4 +1,3 @@
-using System;
 using Spectre.Console;
 
 namespace ColorExample

examples/Columns/Program.cs

@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Net.Http;
 using System.Threading.Tasks;
 using Newtonsoft.Json.Linq;

examples/Tables/Program.cs

@@ -36,6 +36,7 @@ namespace TableExample
                 .AddRow("[blue]Hej[/]", "[yellow]Världen![/]", "");
 
             return new Table()
+                .Centered()
                 .SetBorder(TableBorder.DoubleEdge)
                 .SetHeading("TABLE [yellow]HEADING[/]")
                 .SetFootnote("TABLE [yellow]FOOTNOTE[/]")