Use correct field separator in keywords.txt

The Arduino IDE requires the use of a single true tab separator between the keyword name and identifier. When spaces are used rather than a true tab, the keyword is not highlighted.

Reference:
https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5:-Library-specification#keywords

keywords.txt

@@ -1,14 +1,14 @@
 # Syntax Coloring Map For ModbusIP-ESP8266
 
 # Datatypes (KEYWORD1)
-ModbusRTUSlave  KEYWORD1
-ModbusRTUMaster KEYWORD1
+ModbusRTUSlave	KEYWORD1
+ModbusRTUMaster	KEYWORD1
 ModbusIP	KEYWORD1
 Modbus	KEYWORD1
 TRegister	KEYWORD1
 TTransaction	KEYWORD1
-TAddress    KEYWORD1
-ResultCode  KEYWORD1
+TAddress	KEYWORD1
+ResultCode	KEYWORD1
 
 # Methods and Functions (KEYWORD2)
 master	KEYWORD2
@@ -27,14 +27,14 @@ onGetIreg	KEYWORD2
 onSetIreg	KEYWORD2
 onGetIsts	KEYWORD2
 onSetIsts	KEYWORD2
-removeOnGetCoil KEYWORD2
-removeOnSetCoil KEYWORD2
-removeOnGetHreg KEYWORD2
-removeOnSetHreg KEYWORD2
-removeOnGetIsts KEYWORD2
-removeOnSetIsts KEYWORD2
-removeOnGetIreg KEYWORD2
-removeOnSetIreg KEYWORD2
+removeOnGetCoil	KEYWORD2
+removeOnSetCoil	KEYWORD2
+removeOnGetHreg	KEYWORD2
+removeOnSetHreg	KEYWORD2
+removeOnGetIsts	KEYWORD2
+removeOnSetIsts	KEYWORD2
+removeOnGetIreg	KEYWORD2
+removeOnSetIreg	KEYWORD2
 addCoil	KEYWORD2
 addIsts	KEYWORD2
 addIreg	KEYWORD2
@@ -57,21 +57,21 @@ pullIsts	KEYWORD2
 pushHreg	KEYWORD2
 pullHreg	KEYWORD2
 pullIreg	KEYWORD2
-pullHregToIreg  KEYWORD2
-pullCoilToIsts  KEYWORD2
-pushIstsToCoil  KEYWORD2
-pushIregToHreg  KEYWORD2
-removeHreg  KEYWORD2
-removeIreg  KEYWORD2
-removeCoil  KEYWORD2
-removeIsts  KEYWORD2
-autoConnect KEYWORD2
-disconnect  KEYWORD2
-dropTransactions    KEYWORD2
-isCoil  KEYWORD2
-isHreg  KEYWORD2
-isIsts  KEYWORD2
-isIreg  KEYWORD2
+pullHregToIreg	KEYWORD2
+pullCoilToIsts	KEYWORD2
+pushIstsToCoil	KEYWORD2
+pushIregToHreg	KEYWORD2
+removeHreg	KEYWORD2
+removeIreg	KEYWORD2
+removeCoil	KEYWORD2
+removeIsts	KEYWORD2
+autoConnect	KEYWORD2
+disconnect	KEYWORD2
+dropTransactions	KEYWORD2
+isCoil	KEYWORD2
+isHreg	KEYWORD2
+isIsts	KEYWORD2
+isIreg	KEYWORD2
 
 # Constants and Macros (LITERAL1)
 BIT_VAL	LITERAL1
@@ -82,24 +82,24 @@ ISTS_VAL	LITERAL1
 ISTS_BOOL	LITERAL1
 ResultCode	LITERAL1
 FunctionCode	LITERAL1
-EX_SUCCESS  LITERAL1
-EX_ILLEGAL_FUNCTION LITERAL1
-EX_ILLEGAL_ADDRESS  LITERAL1
-EX_ILLEGAL_VALUE    LITERAL1
-EX_SLAVE_FAILURE    LITERAL1
-EX_ACKNOWLEDGE  LITERAL1
-EX_SLAVE_DEVICE_BUSY    LITERAL1
-EX_MEMORY_PARITY_ERROR  LITERAL1
-EX_PATH_UNAVAILABLE LITERAL1
-EX_DEVICE_FAILED_TO_RESPOND LITERAL1
-EX_GENERAL_FAILURE  LITERAL1
-EX_DATA_MISMACH LITERAL1
-EX_UNEXPECTED_RESPONSE  LITERAL1
-EX_TIMEOUT  LITERAL1
-EX_CONNECTION_LOST  LITERAL1
-EX_CANCEL   LITERAL1
-COIL    LITERAL1
-HREG    LITERAL1
-ISTS    LITERAL1
-IREG    LITERAL1
+EX_SUCCESS	LITERAL1
+EX_ILLEGAL_FUNCTION	LITERAL1
+EX_ILLEGAL_ADDRESS	LITERAL1
+EX_ILLEGAL_VALUE	LITERAL1
+EX_SLAVE_FAILURE	LITERAL1
+EX_ACKNOWLEDGE	LITERAL1
+EX_SLAVE_DEVICE_BUSY	LITERAL1
+EX_MEMORY_PARITY_ERROR	LITERAL1
+EX_PATH_UNAVAILABLE	LITERAL1
+EX_DEVICE_FAILED_TO_RESPOND	LITERAL1
+EX_GENERAL_FAILURE	LITERAL1
+EX_DATA_MISMACH	LITERAL1
+EX_UNEXPECTED_RESPONSE	LITERAL1
+EX_TIMEOUT	LITERAL1
+EX_CONNECTION_LOST	LITERAL1
+EX_CANCEL	LITERAL1
+COIL	LITERAL1
+HREG	LITERAL1
+ISTS	LITERAL1
+IREG	LITERAL1