Revise PHP version table and installation instructions

Updated PHP version requirements and corrected text formatting.

Author: notAreYouScared

docs/guides/php-upgrade.mdx

@@ -12,12 +12,12 @@ table below to check what PHP version you need for your version of Pelican.
 
 | Panel Version | PHP Version        |
 |---------------|--------------------|
-| 1.0.0+        | 8.2, 8.3, 8.4, 8.5 |
+| 1.0.0+        | 8.5, 8.4, 8.3      |
 
 ## Install PHP
 
 In order to install PHP 8.5, you will need to run the following commands. Please keep in mind different operating systems
-may have slightly different requirements for how this commands are formatted.
+may have slightly different requirements for how these commands are formatted.
 
 ```bash
 # Add additional repository for PHP