Update doc

Author: wchen-r7

documentation/modules/exploit/windows/fileformat/office_word_macro.md

@@ -31,6 +31,7 @@ Specifically, this module was tested specifically against:
 
 **BODY** Text to put in the Office document.
 
+
 ## Modification
 
 To use this exploit in a real environment, you will most likely need to modify the docm content.
@@ -44,5 +45,7 @@ Here's one approach you can do:
 
 While editing, you should avoid modifying the following unless you are an advanced user:
 
-* The comments field.
+* The comments field. If you have to modify this, make sure to create 55 empty spaces
+  in front of the payload string. The blank space is for making the payload less obvious
+  at first sight if the user views the file properties.
 * The VB code in the macro.