Use correct separator in keywords.txt

The Arduino IDE requires the use of a tab separator between the name and identifier. Without this tab the keyword is not highlighted.

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

Author: per1234

keywords.txt

@@ -1,9 +1,9 @@
-ByteConvert KEYWORD1
-arrayToVar  KEYWORD2
-varToArray  KEYWORD2
-valToHex    KEYWORD2
-hexToVal    KEYWORD2
-byteToHexString KEYWORD2
-hexStringToByte KEYWORD2
-arrayToString   KEYWORD2
-stringToArray   KEYWORD2
+ByteConvert	KEYWORD1
+arrayToVar	KEYWORD2
+varToArray	KEYWORD2
+valToHex	KEYWORD2
+hexToVal	KEYWORD2
+byteToHexString	KEYWORD2
+hexStringToByte	KEYWORD2
+arrayToString	KEYWORD2
+stringToArray	KEYWORD2