docs: Unmarshal godoc doesn't mention that cbor.Tag is produced for unrecognized tags when decoding into empty interface

[benluddy]

What is the URL of the content?

cbor/decode.go

Lines 40 to 53 in 6bbaf8b

	// To unmarshal CBOR into an empty interface value, Unmarshal uses the
	// following rules:
	//
	// CBOR booleans decode to bool.
	// CBOR positive integers decode to uint64.
	// CBOR negative integers decode to int64 (big.Int if value overflows).
	// CBOR floating points decode to float64.
	// CBOR byte strings decode to []byte.
	// CBOR text strings decode to string.
	// CBOR arrays decode to []interface{}.
	// CBOR maps decode to map[interface{}]interface{}.
	// CBOR null and undefined values decode to nil.
	// CBOR times (tag 0 and 1) decode to time.Time.
	// CBOR bignums (tag 2 and 3) decode to big.Int.

Please describe the problem.

When decoding a tagged data item into an empty interface value, Unmarshal produces a cbor.Tag if it doesn't recognize the tag number. (https://go.dev/play/p/EkGAJ5LnKdI)

[fxamacker]

@benluddy Thanks for spotting this and opening PR #448!

Closed by #448