Add beta-disclaimer on the readme

Author: hilmanski

README.md

@@ -1,5 +1,7 @@
 # SerpApi Ruby Library
 
+> This library is still in beta. You can use our [Google Search Results Ruby SDK](https://github.com/serpapi/google-search-results-ruby) in production.
+
 [![Gem Version](https://badge.fury.io/rb/serpapi.svg)](https://badge.fury.io/rb/serpapi) [![serpapi-ruby](https://github.com/serpapi/serpapi-ruby/actions/workflows/ci.yml/badge.svg)](https://github.com/serpapi/serpapi-ruby/actions/workflows/ci.yml)  [![serpapi-ruby-alternative](https://github.com/serpapi/serpapi-ruby/actions/workflows/sanity_alt.yml/badge.svg)](https://github.com/serpapi/serpapi-ruby/actions/workflows/sanity_alt.yml) [![serpapi-ruby-sanity-1](https://github.com/serpapi/serpapi-ruby/actions/workflows/sanity_1.yml/badge.svg)](https://github.com/serpapi/serpapi-ruby/actions/workflows/sanity_1.yml) [![serpapi-ruby-sanity-2](https://github.com/serpapi/serpapi-ruby/actions/workflows/sanity_2.yml/badge.svg)](https://github.com/serpapi/serpapi-ruby/actions/workflows/sanity_2.yml)
 
 Integrate search data into your Ruby application. This library is the official wrapper for SerpApi (https://serpapi.com).