Merge pull request #560 from DougTW/dm-edits-gpu-plugin

edited gpu_plugin README; changed 2 instances of master to main.

Author: mythi

cmd/gpu_plugin/README.md

@@ -45,7 +45,7 @@ Examples are provided showing how to deploy the plugin either using a DaemonSet
 
 [Pre-built images](https://hub.docker.com/r/intel/intel-gpu-plugin)
 of this component are available on the Docker hub. These images are automatically built and uploaded
-to the hub from the latest master branch of this repository.
+to the hub from the latest main branch of this repository.
 
 Release tagged images of the components are also available on the Docker hub, tagged with their
 release version numbers in the format `x.y.z`, corresponding to the branches and releases in this