Add a real CLI for adjudication

MultiversalDiplomacy/CommandLine/AdjudicateOptions.cs

@@ -0,0 +1,15 @@
+using CommandLine;
+
+namespace MultiversalDiplomacy.CommandLine;
+
+[Verb("adjudicate", HelpText = "Adjudicate a Multiversal Diplomacy game state.")]
+public class AdjudicateOptions
+{
+    [Value(0, HelpText = "Input file describing the game state to adjudicate, or - to read from stdin.")]
+    public string? InputFile { get; set; }
+
+    public static void Execute(AdjudicateOptions args)
+    {
+        throw new NotImplementedException();
+    }
+}

MultiversalDiplomacy/MultiversalDiplomacy.csproj

@@ -7,4 +7,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="CommandLineParser" Version="2.9.1" />
+  </ItemGroup>
+
 </Project>

MultiversalDiplomacy/Program.cs

@@ -1,12 +1,17 @@
-using System;
+using CommandLine;
 
-namespace MultiversalDiplomacy
+using MultiversalDiplomacy.CommandLine;
+
+namespace MultiversalDiplomacy;
+
+internal class Program
 {
-    internal class Program
+    static void Main(string[] args)
     {
-        static void Main(string[] args)
-        {
-            Console.WriteLine("stab");
-        }
+        var parser = Parser.Default;
+        var parseResult = parser.ParseArguments<AdjudicateOptions>(args);
+
+        parseResult
+            .WithParsed(AdjudicateOptions.Execute);
     }
 }