PFW-1362 Show if SpoolJoin is enabled or disabled at bootup

Firmware/SpoolJoin.cpp

@@ -1,4 +1,5 @@
 #include "SpoolJoin.h"
+#include "Marlin.h"
 #include "eeprom.h"
 
 namespace SpoolJoin {
@@ -27,6 +28,15 @@ void SpoolJoin::initSpoolJoinStatus()
     } else {
         updateSpoolJoinStatus(currentStatus);
     }
+
+    // Useful information to see during bootup
+    SERIAL_ECHOPGM("SpoolJoin is ");
+    if (isSpoolJoinEnabled())
+    {
+        SERIAL_ECHOLNPGM("enabled");
+    } else {
+        SERIAL_ECHOLNPGM("disabled");
+    }
 }
 
 void SpoolJoin::toggleSpoolJoin()