Implement change discussed during PR review to the user upgrade guide

Author: rodrigoprimo

wiki/Version-4.0-User-Upgrade-Guide.md

@@ -97,7 +97,7 @@ To continue running code style and code quality checks on JS and/or CSS files, u
 There are two kinds of sniffs which are affected by this:
 1. Sniffs which are specific to JS/CSS and only target JS/CSS code.  
     If you use JS/CSS specific sniffs from either PHP_CodeSniffer itself or from an external standard, remove references to these sniffs from your ruleset.
-2. "Mixed" sniffs, i.e., sniffs which target both PHP as well as JS and/or CSS code.  
+2. "Mixed" sniffs, i.e. sniffs which target both PHP as well as JS and/or CSS code.  
     If an external standard you include in your ruleset contains these type of "mixed" sniffs, contact the maintainer of that standard about making the sniff compatible with PHP_CodeSniffer 4.0.
 
 PHP_CodeSniffer >= 3.13.0 will show you deprecation notices for these sniffs to help you find them.
@@ -352,7 +352,7 @@ Previously a ruleset could already "extend" an array property for a sniff set by
 
 As of PHP_CodeSniffer 4.0, a ruleset can also "extend" the default value of an array property as set in the sniff itself.
 
-The upside of this is that if you want the default value + some extras, you no longer need to duplicate the default value from a sniff array property in your ruleset.  
+The upside of this is that, if you want to use the default value + some extras, you no longer need to duplicate the default values from sniff array properties in your ruleset.  
 The downside is, of course, that if the default value of the property in the sniff changes, your scans may start failing without warning.
 
 #### Upgrading