Preparations for the 1.0 release

* Less cluttered solution layout.
* Move examples to a repository of its own.
* Move Roslyn analyzer to a repository of its own.
* Enable central package management.
* Clean up csproj files.
* Add README file to NuGet packages.

src/Tests/Spectre.Console.Cli.Tests/Data/Settings/ArgumentOrderSettings.cs

@@ -0,0 +1,19 @@
+namespace Spectre.Console.Tests.Data;
+
+public sealed class ArgumentOrderSettings : CommandSettings
+{
+    [CommandArgument(0, "[QUX]")]
+    public int Qux { get; set; }
+
+    [CommandArgument(3, "<CORGI>")]
+    public int Corgi { get; set; }
+
+    [CommandArgument(1, "<BAR>")]
+    public int Bar { get; set; }
+
+    [CommandArgument(2, "<BAZ>")]
+    public int Baz { get; set; }
+
+    [CommandArgument(0, "<FOO>")]
+    public int Foo { get; set; }
+}