Bump version to 0.0.6

- Allow options for wkhtmltopdf to be more customizable
  * page_size: 'A4', 'Letter' can be set via configuration
  * path to the 'wkhtmltopdf' can be set via configuration
  * the 'pdfmarks metadata' can be set via configuration
  * more options will be enabled in upcoming release
- Remove the changelogs section from README.md to CHANGLOGS.md