docs: fix inaccuracies in README

Signed-off-by: Jonathan Norris <jonathan.norris@dynatrace.com>

Author: jonathannorris

README.md

@@ -47,8 +47,8 @@
 
 | Supported Ruby Version | OS                    |
 | ------------ | --------------------- |
-| Ruby 3.4.x   | Windows, MacOS, Linux |
-| Ruby 4.0.x   | Windows, MacOS, Linux |
+| Ruby 3.4.x   | Linux                 |
+| Ruby 4.0.x   | Linux                 |
 
 This project supports all Ruby versions in active maintenance per the [Ruby maintenance schedule](https://www.ruby-lang.org/en/downloads/branches/).
 
@@ -70,7 +70,6 @@ gem install openfeature-sdk
 
 ```ruby
 require 'open_feature/sdk'
-require 'json' # For JSON.dump
 
 # API Initialization and configuration
 
@@ -91,7 +90,7 @@ client = OpenFeature::SDK.build_client
 bool_value = client.fetch_boolean_value(flag_key: 'boolean_flag', default_value: false)
 
 # a details method is also available for more information about the flag evaluation
-# see `ResolutionDetails` for more info
+# see `EvaluationDetails` for more info
 bool_details = client.fetch_boolean_details(flag_key: 'boolean_flag', default_value: false)
 
 # fetching string value feature flag