Fix misspelled keyword in keywords.txt (#36)

per1234 · web-flow · commit f72c573695a5 · 2020-12-17T09:41:25.000+01:00
diff --git a/keywords.txt b/keywords.txt
@@ -50,5 +50,5 @@ inputRegisterWrite	KEYWORD2
 
 COILS	LITERAL1
 DISCRETE_INPUTS	LITERAL1
-HOLIDING_REGISTERS	LITERAL1
+HOLDING_REGISTERS	LITERAL1
 INPUT_REGISTERS	LITERAL1
