feat: parse into a Document that keeps order and comments

Assisted-by: DeepSeek V4.1 Flash

fuzz_test.go

@@ -41,7 +41,7 @@ func FuzzParse(f *testing.F) {
 		f.Add([]byte(s))
 	}
 	f.Fuzz(func(t *testing.T, data []byte) {
-		tree, err := Parse(data)
+		tree, err := ParseMap(data)
 		if err != nil {
 			return
 		}
@@ -49,7 +49,7 @@ func FuzzParse(f *testing.F) {
 		if err != nil {
 			t.Fatalf("marshal of a parsed tree failed: %v\ntree: %#v", err, tree)
 		}
-		re, err := Parse(out)
+		re, err := ParseMap(out)
 		if err != nil {
 			t.Fatalf("re-parse of the emitted document failed: %v\ndoc:\n%s", err, out)
 		}