Adds helper function to add definition to the script library.

BuildLibrary.hpp

@@ -14,7 +14,9 @@ class BuildLibrary {
     static PkmnLib::Library::TimeOfDay GetTime() { return PkmnLib::Library::TimeOfDay::Morning; }
 
 public:
-    static PkmnLib::Battling::BattleLibrary* Build(const std::string& pathString) {
+    static PkmnLib::Battling::BattleLibrary*
+    Build(const std::string& pathString,
+          std::function<void(PkmnLib::Battling::ScriptResolver*)> onScriptInitialize = {}) {
         auto path = std::filesystem::path(pathString);
         auto* typesLibrary = BuildTypes::Build(path / "Types.csv");
         auto* natureLibrary = BuildNatures::Build(path / "Natures.csv");
@@ -41,6 +43,9 @@ public:
 
         scriptResolver->Initialize(battleLib);
 
+        if (onScriptInitialize) {
+            onScriptInitialize(scriptResolver);
+        }
         auto asScriptResolver = dynamic_cast<AngelScriptResolver*>(scriptResolver);
 
         for (const auto& dirEntry : std::filesystem::recursive_directory_iterator(scriptsPath)) {