(docs) Add maintenance notice

@joshcooper is this the appropriate support tier?

diff --git a/README.md b/README.md
index 520c69944d1e9c1a922f6c28e5a669520683e335..7844f3ae33d11054f88b442b559616e77e6b4bd8 100644 (file)
--- a/README.md
+++ b/README.md
@@ -5,6 +5,10 @@
 [![Modules Status](https://github.com/puppetlabs/puppetlabs-mailalias_core/workflows/Unit%20Tests%20with%20nightly%20Puppet%20gem/badge.svg?branch=main)](https://github.com/puppetlabs/puppetlabs-mailalias_core/actions) 
 [![Modules Status](https://github.com/puppetlabs/puppetlabs-mailalias_core/workflows/Unit%20Tests%20with%20released%20Puppet%20gem/badge.svg?branch=main)](https://github.com/puppetlabs/puppetlabs-mailalias_core/actions)
 
+> This module is maintained by Puppet, but we have no plans for future feature development. We will keep it working with current versions of Puppet, but new feature development will come from community contributions. It does not qualify for Puppet Support plans.
+>
+> [tier:maintenance-mode]
+
 
 #### Table of Contents