【feature request】ROLL provides Dockerfiles for Ascend Docker images

ROLL provides Dockerfiles for Ascend Docker images, which are built on the CANN base image. Serving as a design reference, it supports developers in building their own Ascend images, while integrating necessary toolchains for accuracy and performance, as well as the image OVERVIEW.md.
OS: Ubuntu
Expected Delivery Date: 2026/04/30

Locate the requested Dockerfiles and image OVERVIEW.md in the repository, then review how the images use the CANN base image. Identify the necessary toolchains for Ascend accuracy and performance; done means the Dockerfiles provide the requested build references and the overview documents them.

Written by the indexing model from the issue text.