Syntax updates to TaskList for embedded snippets
Syntax updates to TaskList for embedded snippets

 - Simplify snippet for "the call to create the authorized Cloud Datastore
   service object" to just a require statement and variable creation
 - Use double quotes consistently
 - Remove 2 unnecessary newlines to shorten sample showing listing tasks

GoogleCloudPlatform/ruby-docs-samples,GoogleCloudPlatform/ruby-docs-samples,GoogleCloudPlatform/ruby-docs-samples,GoogleCloudPlatform/ruby-docs-samples