Update, add new container image and document purpose of them

Signed-off-by: Joachim Wiberg <[email protected]>

README.md

@@ -1,28 +1,34 @@
 # curiOS — a slim curated container OS
 
-curiOS, pronounced curious, is a slim curated base of system containers.
-
-curiOS is a wrapper around [Buildroot][0] for creating container images for
-uploading to Docker Hub or similar.  Buildroot is an SDK for building embedded
-Linux distributions.  It handles the removal of man pages, shared files, and
-many pieces not germane to running on an embedded platform, and, as it turns
-out, containers.
+curiOS, pronounced curious, is a slim curated base of containers.
 
 
 ## AppStore
 
 The [KernelKit AppStore][2] on GHCR provides the following readily available
 container images for both AMD64 and ARM64 hosts:
 
- - [curiOS system][3]: Dropbear SSH daemon, mini-snmpd, netopeer-cli
+ - [curiOS system][3]: A system container, example of how to run multiple
+   services: Dropbear SSH daemon, mini-snmpd, netopeer-cli, ntpd, nftables
  - [curiOS ntpd][4]: ISC ntpd supports [multicasting NTP][10] to a subnet
- - [curiOS nftables][5]: Set up advanced netfilter rules
+ - [curiOS nftables][5]: Useful for advanced netfilter setups.  At startup
+   loads `/etc/netfilter.conf` and calls `nft flush ruleset` at shutdown
+ - [curiOS httpd][6]: Tiny web server container based on BusyBox httpd,
+   suitable for embedding in a firmware image as an example container
 
-> All images contain the same [BusyBox][1] toolset.
+> **Note:** the system container is very useful for staging/development
+> before deploying any of the slim application containers, because they
+> can be very difficult to debug (none or little tooling in image).
 
 
 ## Origin & References
 
+curiOS is a wrapper around [Buildroot][0] for creating container images for
+uploading to Docker Hub or similar.  Buildroot is an SDK for building embedded
+Linux distributions.  It handles the removal of man pages, shared files, and
+many pieces not germane to running on an embedded platform, and, as it turns
+out, containers.
+
 curiOS is a fork of https://github.com/brianredbeard/coreos_buildroot
 
 [0]: https://buildroot.org
@@ -31,4 +37,5 @@ curiOS is a fork of https://github.com/brianredbeard/coreos_buildroot
 [3]: https://github.com/orgs/kernelkit/packages/container/package/curios
 [4]: https://github.com/orgs/kernelkit/packages/container/package/curios-ntpd
 [5]: https://github.com/orgs/kernelkit/packages/container/package/curios-nftables
+[6]: https://github.com/orgs/kernelkit/packages/container/package/curios-httpd
 [10]: https://www.ntp.org/documentation/4.2.8-series/discover/