README.md: target c9s because ELN is more aggressive and has bugs

A while ago there was PR#17 that emphasised centos stream9 instead
of fedora:eln. We could not take it back then because the iso
installer was not quite ready for centos and there were hardcoded
EFI names. But now everything is in place so this cherry picks
the original changes from Colin.

See also osbuild#17

README.md

@@ -23,10 +23,10 @@ $ podman machine start
 
 ## 🚀 Examples
 
-The following example builds a [Fedora ELN](https://docs.fedoraproject.org/en-US/eln/) bootable container into a QCOW2 image for the architecture you're running
+The following example builds a [CentoOS Stream9](https://centos.org/stream9/) bootable container into a QCOW2 image for the architecture you're running
 the command on.
 
-The `fedora-bootc:eln` base image does not include a default user. This example injects a [user configuration file](#-build-config)
+The `centos-bootc:stream9` base image does not include a default user. This example injects a [user configuration file](#-build-config)
 by adding a volume-mount for the local file as well as the `--config` flag to the bootc-image-builder container.
 
 The following command will create a QCOW2 disk image. First, create `./config.json` as described above to configure user access.
@@ -42,7 +42,7 @@ sudo podman run \
     -v $(pwd)/output:/output \
     quay.io/centos-bootc/bootc-image-builder:latest \
     --type qcow2 \
-    quay.io/centos-bootc/fedora-bootc:eln
+    quay.io/centos-bootc/centos-bootc:stream9
 ```
 
 ### Using local containers
@@ -219,10 +219,10 @@ For example:
   --env AWS_PROFILE=default \
   quay.io/centos-bootc/bootc-image-builder:latest \
   --type ami \
-  --aws-ami-name fedora-bootc-ami \
+  --aws-ami-name centos-bootc-ami \
   --aws-bucket fedora-bootc-bucket \
   --aws-region us-east-1 \
-  quay.io/centos-bootc/fedora-bootc:eln
+  quay.io/centos-bootc/centos-bootc:stream9
 ```
 
 Notes:
@@ -258,10 +258,10 @@ $ sudo podman run \
   --env-file=aws.secrets \
   quay.io/centos-bootc/bootc-image-builder:latest \
   --type ami \
-  --aws-ami-name fedora-bootc-ami \
-  --aws-bucket fedora-bootc-bucket \
+  --aws-ami-name centos-bootc-ami \
+  --aws-bucket centos-bootc-bucket \
   --aws-region us-east-1 \
-  quay.io/centos-bootc/fedora-bootc:eln
+  quay.io/centos-bootc/centos-bootc:stream9
 ```
 
 ## 💽 Volumes
@@ -315,7 +315,7 @@ sudo podman run \
     quay.io/centos-bootc/bootc-image-builder:latest \
     --type qcow2 \
     --config /config.json \
-    quay.io/centos-bootc/fedora-bootc:eln
+    quay.io/centos-bootc/centos-bootc:stream9
 ```
 
 ### Users (`user`, array)
@@ -382,11 +382,11 @@ ssh -i /path/to/private/ssh-key alice@ip-address
 ```
 
 Note that if you do not provide a password for the provided user, `sudo` will not work unless passwordless sudo
-is configured. The base image `quay.io/centos-bootc/fedora-bootc:eln` does not configure passwordless sudo.
+is configured. The base image `quay.io/centos-bootc/centos-bootc:stream9` does not configure passwordless sudo.
 This can be configured in a derived bootc container by including the following in a Containerfile.
 
 ```dockerfile
-FROM quay.io/centos-bootc/fedora-bootc:eln
+FROM quay.io/centos-bootc/centos-bootc:stream9
 ADD wheel-passwordless-sudo /etc/sudoers.d/wheel-passwordless-sudo
 ```