Add correct description for freeze ConfigItem

Author: spencertransier

lib/fastlane/plugin/wpmreleasetoolkit/actions/common/setfrozentag_action.rb

@@ -68,7 +68,7 @@ def self.available_options
                                        optional: false,
                                        type: String),
           FastlaneCore::ConfigItem.new(key: :freeze,
-                                       description: 'The GitHub milestone',
+                                       description: 'If true, the action will add the ❄️ emoji to the milestone title',
                                        optional: false,
                                        default_value: true,
                                        type: Boolean),