Move Spectre.Console.Cli to it's own package

src/Spectre.Console.Cli/IFlagValue.cs

@@ -0,0 +1,22 @@
+namespace Spectre.Console.Cli;
+
+/// <summary>
+/// Represents a flag with an optional value.
+/// </summary>
+public interface IFlagValue
+{
+    /// <summary>
+    /// Gets or sets a value indicating whether or not the flag was set or not.
+    /// </summary>
+    bool IsSet { get; set; }
+
+    /// <summary>
+    /// Gets the flag's element type.
+    /// </summary>
+    Type Type { get; }
+
+    /// <summary>
+    /// Gets or sets the flag's value.
+    /// </summary>
+    object? Value { get; set; }
+}