ESP8266 feather huzzah wiring for MFRC522
use Wemos table from your link. here is the mapping to esp8266 io pins

RST/Reset   D3 = io 0
SPI SS      D8 = io 15
SPI MOSI    D7 = io 13
SPI MISO    D6 = io 12
SPI SCK     D5 = io 14


If you want, you can use any pin for SS and reset. See the examples.

#define SS_PIN 4
#define RST_PIN 5
MFRC522 mfrc522(SS_PIN, RST_PIN);