Fix ruby version (#3242)

justin808 · web-flow · commit 275fbb56e6b0 · 2021-12-04T14:18:31.000+01:00
Corresponding to the gemspec. https://github.com/rails/webpacker/blob/master/webpacker.gemspec#L18
diff --git a/README.md b/README.md
@@ -52,7 +52,7 @@ leaving Webpack responsible solely for app-like JavaScript, or it can be used ex
 
 ## Prerequisites
 
-- Ruby 2.4+
+- Ruby 2.7+
 - Rails 5.2+
 - Node.js 12.13.0+ || 14+
 - Yarn
