rlp: fix documentation for booleans

Fixes #19367

rlp/decode.go

@@ -115,15 +115,17 @@ type Decoder interface {
 // type, Decode will return an error. Decode also supports *big.Int.
 // There is no size limit for big integers.
 //
+// To decode into a boolean, the input must contain an unsigned integer
+// of value zero (false) or one (true).
+//
 // To decode into an interface value, Decode stores one of these
 // in the value:
 //
 //	  []interface{}, for RLP lists
 //	  []byte, for RLP strings
 //
-// Non-empty interface types are not supported, nor are booleans,
-// signed integers, floating point numbers, maps, channels and
-// functions.
+// Non-empty interface types are not supported, nor are signed integers,
+// floating point numbers, maps, channels and functions.
 //
 // Note that Decode does not set an input limit for all readers
 // and may be vulnerable to panics cause by huge value sizes. If

rlp/encode.go

@@ -73,10 +73,12 @@ type Encoder interface {
 // An unsigned integer value is encoded as an RLP string. Zero always
 // encodes as an empty RLP string. Encode also supports *big.Int.
 //
+// Boolean values are encoded as unsigned integers zero (false) and one (true).
+//
 // An interface value encodes as the value contained in the interface.
 //
-// Boolean values are not supported, nor are signed integers, floating
-// point numbers, maps, channels and functions.
+// Signed integers are not supported, nor are floating point numbers, maps,
+// channels and functions.
 func Encode(w io.Writer, val interface{}) error {
 	if outer, ok := w.(*encbuf); ok {
 		// Encode was called by some type's EncodeRLP.