Plugin short description less than 150 characters. (WordPress#59661)

Co-authored-by: andrewfleming <ajfleming@git.wordpress.org>
Co-authored-by: tellthemachines <isabel_brison@git.wordpress.org>
Co-authored-by: swissspidy <swissspidy@git.wordpress.org>

readme.txt

@@ -5,7 +5,7 @@ Stable tag: V.V.V
 License: GPLv2 or later
 License URI: http://www.gnu.org/licenses/gpl-2.0.html
 
-The Gutenberg plugin provides editing, customization, and site building features to WordPress. This beta plugin allows you to test bleeding-edge features before they land in future WordPress releases.
+The Gutenberg plugin adds editing, customization, and site building to WordPress. Use it to test beta features before their official release.
 
 == Description ==