concepts: Include image generation on coreutils replacement

Improve the description of the migration plan mentioning image generation.

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>

content/concepts/coreutils-replacement.md

@@ -242,5 +242,6 @@ The following guidelines will be followed to assure a smooth transition minimizi
 - Determine the list of tools supported and successfully tested provided by `uutils-coreutils`.
 - Create a new package based on `uutils-coreutils` named `coreutils-uutils` with all the tools that are supported and successfully tested.
 - For missing tools a replacement will be provided on case by case basis.
+- Generate APT and OSTree based images for target and minimal configuration.
 
 Due to the [Apertis release flow]( {{< ref "release-flow.md" >}} ) this process will start on development releases allowing any potential issue to be addressed before a stable point release, with the possibility of switching back to `coreutils-gplv2` if a proper fix cannot be implemented on time.