add update message to readme

Author: gilesknap

.vscode/settings.json

@@ -16,6 +16,7 @@
         "Beamlines",
         "blxxi",
         "blxxt",
-        "klogout"
+        "klogout",
+        "MVME"
     ]
 }

README.rst

@@ -32,3 +32,27 @@ Organization   https://github.com/epics-containers
     when included in index.rst
 
 See https://epics-containers.github.io for more detailed documentation.
+
+Update for March 2023
+=====================
+
+Since the documentation for epics-containers was first published in Oct 2021,
+there have been significant updates to the projects in this organization.
+
+The documentation is now being updated to reflect these changes.
+
+Notable improvements are:
+
+- The developer experience has now been improved.
+
+  - Addition of a developer container with all the tools needed to build
+    and test the epics-containers projects included.
+  - Addition of a CLI tool to assist building deploying and managing
+    containerize EPICS IOCs.
+
+- overhaul of the container build approach to minimize cache busting and
+  improve build times.
+
+- Addition of support for IOCS running on MVME5500 with RTEMS 5. (this
+  could be extended to any cross-compiled architectures that use a
+  telnet shell and get their binaries from share file-systems (such as TFTP))