Initial work on scripts

PkmnLib.Dynamic/ScriptHandling/ScriptContainer.cs

@@ -1,4 +1,5 @@
 using System.Collections;
+using System.Diagnostics.CodeAnalysis;
 
 namespace PkmnLib.Dynamic.ScriptHandling;
 
@@ -6,7 +7,14 @@ public class ScriptContainer : IEnumerable<ScriptContainer>
 {
     private Script? _script = null;
 
+    [MemberNotNullWhen(false, nameof(ScriptHandling.Script))]
     public bool IsEmpty => _script is null;
+    
+    public Script? Script
+    {
+        get => _script;
+        set => _script = value;
+    }
 
     /// <inheritdoc />
     public IEnumerator<ScriptContainer> GetEnumerator()