Core: Update the package.json description

Indicate this version of Migrate helps with updating jQuery to 3.x, not 3.0+.

package.json

@@ -1,7 +1,7 @@
 {
 	"name": "jquery-migrate",
 	"title": "jQuery Migrate",
-	"description": "Migrate older jQuery code to jQuery 3.0+",
+	"description": "Migrate older jQuery code to jQuery 3.x",
 	"main": "dist/jquery-migrate.js",
 	"version": "3.5.3-pre",
 	"type": "module",