Make comment toggling work for IJ1 macro language

See:
* #18 (comment)
* https://forum.image.sc/t/toggle-commenting-out-ijm-code-in-script-editor/247490

Author: ctrueden

src/main/java/org/scijava/ui/swing/script/highliters/ImageJMacroTokenMaker.java

@@ -2429,6 +2429,11 @@ public void addToken(final char[] array, final int start, final int end,
 		zzStartRead = zzMarkedPos;
 	}
 
+	@Override
+	public String[] getLineCommentStartAndEnd(int languageIndex) {
+		return new String[] { "//", null };
+	}
+
 	/**
 	 * Returns the first token in the linked list of tokens generated from
 	 * <code>text</code>. This method must be implemented by subclasses so they