Fixed spelling of 'zeros' in the REST template.
- Added validation in `v2/AppsResource` to return a detailed error message and a `400` status code in case container options are specified for a task that uses the default command executor.
- Added more severe logging if somehow container options are passed when using the default command executor.
Updated the doc generation script to _not_ elide leading whitespace from lines read from the doc template.
- Updated the doc template to describe the interplay between container options and executors.
- Generated new REST docs.