Update readme.txt

Updates the stable tag to 3.1

Author: mhkuu

readme.txt

@@ -5,7 +5,7 @@ Requires at least: 6.1
 Tested up to: 6.2
 License: GPLv3
 License URI: http://www.gnu.org/licenses/gpl.html
-Stable tag: 3.0.1
+Stable tag: 3.1
 Requires PHP: 7.2.5
 
 WordPress plugin that adds the content of all ACF fields to the Yoast SEO score analysis.