We've added a new section to the Liferay Development Guide covering the Resources Importer: https://www.liferay.com/documentation/liferay-portal/6.1/development/-/ai/6-1-importing-resources-with-themes. Liferay’s Resources Importer is a tool that allows a theme developer to have files and web content automatically imported into the portal when a theme is deployed. This is a great way for theme developers to provide a sample context that optimizes the design of their theme.

In this section, you can find out

• what the Resources Importer does and why it's useful.
• how to download and install the Resources Importer.
• how to declare the resources importer as a dependency of your theme.
• how to configure resources to be imported into a site template or directly into a site.
• how to develop resources and add them to your theme.
• how to declare the pages, layout templates, portlets and content that should appear in your theme's site or site template.
• where to find examples of themes that show the resources importer in action.

If you're considering developing themes for Liferay Marketplace, make sure to check out this guide!