feat: support TOML 1.1

Assisted-by: GLM 5.3 Flash

interpres.go

@@ -196,7 +196,8 @@ type Unmarshaler interface {
 	UnmarshalTOML(data any) error
 }
 
-// Marshal returns the TOML 1.0 encoding of v.
+// Marshal returns the TOML encoding of v. The output stays within TOML 1.0,
+// so it is valid under both TOML 1.0 and 1.1.
 //
 // Marshal traverses v using reflection and applies the following rules:
 //