Add method documentation, update comments

Add resource documentation for configurator.
Update comments for resource constants.
Simplify resource merging in auto detector.

Author: robertlaurin

resource-detectors/lib/opentelemetry/resource/detectors/auto_detector.rb

@@ -16,10 +16,7 @@ module AutoDetector
         ].freeze
 
         def detect
-          resources = DETECTORS.map(&:detect)
-          resources.reduce(OpenTelemetry::SDK::Resources::Resource.create) do |accumulated, detected|
-            accumulated.merge(detected)
-          end
+          DETECTORS.map(&:detect).reduce(:merge)
         end
       end
     end

sdk/lib/opentelemetry/sdk/configurator.rb

@@ -34,6 +34,11 @@ def logger
         @logger ||= Logger.new(STDOUT)
       end
 
+      # Accepts a resource object that is merged with the default telemetry sdk
+      # resource. The use of this method is optional, and is provided as means
+      # to add additional resource information.
+      #
+      # @param [Resource] new_resource The resource to be merged
       def resource=(new_resource)
         @resource = @resource.merge(new_resource)
       end

sdk/lib/opentelemetry/sdk/resources/constants.rb

@@ -28,7 +28,7 @@ module Constants
           # The name of the telemetry library.
           name: 'telemetry.sdk.name',
 
-          # The language of telemetry library and of the code instrumented with it.
+          # The language of the telemetry library and of the code instrumented with it.
           language: 'telemetry.sdk.language',
 
           # The version string of the telemetry library