- add - highlight for PUBLIC, PRIVATE, PROTECTED keywords

Author: Serhioromano

example.iecst

@@ -5,7 +5,8 @@ CONFIGURATION DefaultCfg
   TASK NewTask  (INTERVAL := T#20ms);
   PROGRAM Main WITH NewTask : PLC_PRG;
 END_CONFIGURATION
- PROGRAM demo
+
+PROGRAM demo
   VAR_EXTERNAL
     Start_Stop: BOOL;
   END_VAR
@@ -18,7 +19,11 @@ END_CONFIGURATION
     Start_Stop := TRUE;
   END_IF
 END_PROGRAM;
- /* Get a square of the circle */
+
+FUNCTION_BLOCK PRIVATE MyName EXTENDS AnotherName
+	
+END_FUNCTION_BLOCK
+/* Get a square of the circle */
 FUNCTION csq : REAL 
   VAR_INPUT
     r: REAL;

iecst.js

@@ -22,6 +22,7 @@ function hljsDefineIECST(hljs) {
             keyword:
                 "if then end_if elsif else case of end_case " +
                 "to do by while repeat end_while end_repeat for end_for from " +
+                "private public protected " +
                 "or and not xor le ge eq ne ge lt constant return exit at retain non_retain task with until using extend",
             title:
                 "program end_program function end_function function_block end_function_block configuration " +