[nostalgia] Update developer-handbook non-error return

developer-handbook.md

@@ -265,7 +265,7 @@ ox::Error engineCode() noexcept {
 	auto [val, err] = foo(1);
 	oxReturnError(err);
 	doStuff(val);
-	return OxError(0);
+	return {};
 }
 
 void anyCode() {
@@ -288,7 +288,7 @@ ox::Error engineCode() noexcept {
 	auto valerr = foo(1);
 	oxReturnError(valerr);
 	doStuff(valerr.value);
-	return OxError(0);
+	return {};
 }
 ```
 
@@ -426,7 +426,7 @@ constexpr ox::Error model(T *h, ox::CommonPtrWith<NostalgiaPalette> auto *pal) n
 	// it is also possible to provide the type name and type version as function arguments
 	//h->setTypeInfo("net.drinkingtea.nostalgia.core.NostalgiaPalette", 1);
 	oxReturnError(h->field("colors", &pal->colors));
-	return OxError(0);
+	return {};
 }
 
 template<typename T>
@@ -438,7 +438,7 @@ constexpr ox::Error model(T *h, ox::CommonPtrWith<NostalgiaGraphic> auto *ng) no
 	oxReturnError(h->field("defaultPalette", &ng->defaultPalette));
 	oxReturnError(h->field("pal", &ng->pal));
 	oxReturnError(h->field("pixels", &ng->pixels));
-	return OxError(0);
+	return {};
 }
 ```
 
@@ -475,7 +475,7 @@ constexpr Error model(T *h, ox::CommonPtrWith<FileAddress::Data> auto *obj) noex
 	oxReturnError(h->fieldCString("path", &obj->path));
 	oxReturnError(h->fieldCString("constPath", &obj->path));
 	oxReturnError(h->field("inode", &obj->inode));
-	return OxError(0);
+	return {};
 }
 
 template<typename T>
@@ -492,7 +492,7 @@ constexpr Error model(T *io, ox::CommonPtrWith<FileAddress> auto *fa) noexcept {
 		fa->m_type = static_cast<FileAddressType>(type);
 		oxReturnError(io->field("data", UnionView(&fa->m_data, static_cast<int>(fa->m_type))));
 	}
-	return OxError(0);
+	return {};
 }
 
 ```