This documentation was written by Jordan Cormack for the Unitree A1.
There is a User Manual and Developer Guide, which provide more information on getting started with the A1, but a lot of information is missing or unclear, especially in terms of ROS/autonomy.
Make sure to read the safety information in the user manual carefully, and keep fingers well clear of the motors/joints/legs. The dog is easily capable of removing a finger if you put it in the wrong place.
Unitree A1 Getting Started
Starting ROS/SLAM
Custom Payload/Backpack Guide