README.md in grumlin-1.0.0.rc6 vs README.md in grumlin-1.0.0.rc7

@@ -22,9 +22,14 @@
 - [Development](#development)
 - [Contributing](#contributing)
 - [License](#license)
 - [Code Of Conduct](#code-of-conduct)
 
+
+## Dependencies
+
+Grumlin works with ruby >= 2.7, but it's recommended to use 3.1 due to [zlib warnings](https://github.com/socketry/async-websocket/issues/42).
+
 ## Install
 
 Add this line to your application's Gemfile:
 
 ```ruby