Fix typo in Invoke-Formatter documentation

Added a missing word in example 3 and changed to correct code formatting in the same heading.

Author: baardhermansen

reference/ps-modules/PSScriptAnalyzer/Invoke-Formatter.md

@@ -9,11 +9,12 @@ schema: 2.0.0
 # Invoke-Formatter
 
 ## SYNOPSIS
+
 Formats a script text based on the input settings or default settings.
 
 ## SYNTAX
 
-```
+```powershell
 Invoke-Formatter [-ScriptDefinition] <string> [[-Settings] <Object>] [[-Range] <int[]>]
  [<CommonParameters>]
 ```
@@ -76,7 +77,7 @@ function foo
 }
 ```
 
-### EXAMPLE 3 - Format the input script text using the settings defined a `.psd1` file
+### EXAMPLE 3 - Format the input script text using the settings defined in a `.psd1` file
 
 ```powershell
 Invoke-Formatter -ScriptDefinition $scriptDefinition -Settings /path/to/settings.psd1