encoding.base64: fix doc comment examples

vlib/encoding/base64/base64.c.v

@@ -187,7 +187,7 @@ mut:
 
 // decode decodes the base64 encoded `string` value passed in `data`.
 // Please note: If you need to decode many strings repeatedly, take a look at `decode_in_buffer`.
-// Example: assert base64.decode('ViBpbiBiYXNlIDY0') == 'V in base 64'
+// Example: assert base64.decode('ViBpbiBiYXNlIDY0') == 'V in base 64'.bytes()
 pub fn decode(data string) []u8 {
 	mut size := i64(data.len) * 3 / 4
 	if size <= 0 || data.len % 4 != 0 {
@@ -218,7 +218,7 @@ pub fn decode_str(data string) string {
 // encode encodes the `[]u8` value passed in `data` to base64.
 // Please note: base64 encoding returns a `string` that is ~ 4/3 larger than the input.
 // Please note: If you need to encode many strings repeatedly, take a look at `encode_in_buffer`.
-// Example: assert base64.encode('V in base 64') == 'ViBpbiBiYXNlIDY0'
+// Example: assert base64.encode('V in base 64'.bytes()) == 'ViBpbiBiYXNlIDY0'
 pub fn encode(data []u8) string {
 	return alloc_and_encode(data.data, data.len)
 }