docs: More fixes

Put container image reference first, other cleanups.

docs/index.md

@@ -1,12 +1,20 @@
 # Goals
 
-This project's toplevel goal is to create base *bootable* container images
-from Fedora ELN and CentOS Stream packages.
+This project's toplevel goal is to maintain default definitions for
+base *bootable* container images, locked with Fedora ELN and CentOS Stream 9.
 
 ## Status
 
 This is an in-development project not intended for production use yet.
 
+## Container images
+
+The primary output of this project is container images.  The current
+main development target is [Fedora ELN](https://docs.fedoraproject.org/en-US/eln/)
+and there is one image built:
+
+- `quay.io/centos-boot/fedora-tier-1:eln`
+
 ## Trying it out
 
 See [install.md](./install.md).
@@ -23,9 +31,10 @@ include Ignition for example.
 
 ## Differences from RHEL CoreOS
 
-We sometimes say that RHEL CoreOS [has FCOS as an upstream](https://github.com/openshift/os/blob/master/docs/faq.md#q-what-is-coreos) but this is only
-kind of true; RHEL CoreOS includes a subset of FCOS content, and is lifecycled
-with OCP.
+We sometimes say that RHEL CoreOS
+[has FCOS as an upstream](https://github.com/openshift/os/blob/master/docs/faq.md#q-what-is-coreos)
+but this is only kind of true; RHEL CoreOS includes a subset of FCOS content,
+and is lifecycled with OCP.
 
 An explicit goal of this project is to produce bootable container images
 that can be used as *base images* for RHEL CoreOS; for more on this, see e.g.
@@ -35,53 +44,23 @@ that can be used as *base images* for RHEL CoreOS; for more on this, see e.g.
 
 It is an explicit goal that CentOS boot also becomes a "base input" to RHEL for Edge.
 
-## Demonstration base images for Project CentOS boot
-
-These images are technology demonstrators, not for production use. The
-intention is that these images are generated by the OS vendor or
-distribution.  
-Or, you can fork this repository and generate your own via
-`rpm-ostree compose image`.
-
-## Operating system sources
-
-At the moment these demonstration builds use Fedora ELN and CentOS Stream 9.
-
-## Tiers
-
-### Tier 0
+## Understanding "tiers"
 
-This is the basic tier; it has effectively just:
+There is a "tier-0" image, but it is not yet being automatically built.  The "tier-0"
+contains:
 
-- kernel systemd selinux-policy-targeted bootc
+- kernel
+- systemd
+- bootc
+- selinux-policy-targeted
 
-You are generally going to need to generate derived images from this; installing
-it on its own will boot to a system with no automatic networking support, no SSH,
-and no default passwords etc.
-
-### Tier 1
-
-This is larger system.
+The tier-1 is a reasonably large system:
 
 - NetworkManager, chrony
 - rpm-ostree (to install packages and in case it's useful "day 2")
 - openssh-server
 
-At the current time, it does not include Ignition or cloud-init; so you will
-still need to derive from it in order to inject a mechanism to log in in many
-cases.  However, it will work to install it using e.g. Anaconda and set up
-users and passwords that way.
-
-## Image matrix (Fedora)
-
-- `quay.io/centos-boot/fedora-tier-1:eln`
-
-### More about image sources
-
-The current manifest definitions [tier-0](tier-0) and [tier-1](tier-1) were
-forked from Fedora CoreOS, but significantly cut down.
-
-The existing content set is obviously subject to change and debate.
+The content set for these images is subject to change.
 
 ## Building