Add support for ARM on Docs

[dralquinta]

Hello,

When following documentation there is no support for ARM Kubernetes Clusters, hence when deploying the bundle, you will get the following error on pod startup:

│ admission standard_init_linux.go:228: exec user process caused: exec format error                                                                                                                                             │
│ redis-enterprise-operator standard_init_linux.go:228: exec user process caused: exec format error 

Could you please add support for ARM?

[dralquinta]

Further review of available tags on github show that image is only available for AMD64 architecture