[Morse] Added note about SX126x support

examples/Morse/Morse_Transmit/Morse_Transmit.ino

@@ -5,10 +5,11 @@
    SX1278's FSK modem.
 
    Other modules that can be used for Morse:
-    - SX1272/73/76/77/79
+    - SX127x/RFM9x
     - RF69
     - SX1231
     - CC1101
+    - SX126x
 */
 
 // include the library