Where can I find documentation for FreeRTOS?

Documentation for the Analog Devices FreeRTOS product can be found in the adi_freertos_user_guide.pdf which is shipped in the docs directory of the product zip file.

General documentation on the FreeRTOS real-time operating system can be found on the FreeRTOS website.
There is a vast array of documentation, examples and programming guides on the FreeRTOS website.

We recommend that developers new to FreeRTOS start with the ADI FreeRTOS User Guide mentioned above, and the FreeRTOS Quick Start Guide.