powerly release v1.1.0

Features

• add validate wrapper for Validation class
• add Validation class to validate method results

Other changes

• fix README.md image and text size
• decrease legend font size in StepThree
• add type fields for model, statistic and measure in StepOne
• add active binding for StepOne in StepThree
• rename from quantile to percentile in StepThree
• add validation example figure to documentation
• add documentation for validate function
• add validate function to roxygen2 @seealso tags
• fix typo in documentation of powerly function
• update README.md to include validation example
• recreate DESCRIPTION and NAMESPACE for validation
• generate documentation file for validation function
• update documentation files for powerly and generate_model
• update news to mention addition of validation procedure