Setup advice for embedded c workflow

Hi,

I am new to Docker. Previously I have developed embedded C using Jenkins, with development on Windows 10.
I would like to incorporate Github into the workflow, and realise than Docker is the best route to support this.
The first step would be to try out Docker such that it simply beautified the source files on checkin to a branch in Github.
Previously I have used Astyle and Uncrustify for this.

What are the steps needed to create a Docker image with a C beautifier.
I have Docker Desktop for Windows installed, but need a step by step guide to getting the image built and running. The image needs to run locally prior to commit and also on Github after a commit. Not sure if this makes a difference to how the image is built.
The examples seem to start with echo hello world and then jump to something a lot more complicated.

Thanks for any help