docs: add depreciation message (#612)

Author: ocofaigh

.secrets.baseline

@@ -3,7 +3,7 @@
     "files": "go.sum|^.secrets.baseline$",
     "lines": null
   },
-  "generated_at": "2024-10-18T12:26:02Z",
+  "generated_at": "2025-07-21T13:54:00Z",
   "plugins_used": [
     {
       "name": "AWSKeyDetector"
@@ -82,7 +82,7 @@
         "hashed_secret": "3f0155e75563ab3adc0505000a86da5baa207d1f",
         "is_secret": false,
         "is_verified": false,
-        "line_number": 59,
+        "line_number": 77,
         "type": "Secret Keyword",
         "verified_result": null
       }

README.md

@@ -1,5 +1,23 @@
 # Terraform IBM Observability agents module
 
+---
+
+:warning: **Deprecated**: This module has been deprecated in favour of the following 2 modules:
+- [terraform-ibm-monitoring-agent](https://github.com/terraform-ibm-modules/terraform-ibm-monitoring-agent)
+- [terraform-ibm-logs-agent](https://github.com/terraform-ibm-modules/terraform-ibm-logs-agent)
+
+
+Migration:
+- It is possible to migrate the logs agent using a terraform moved block like so which would mean the upgrade would be an update-in-place instead of a destroy / re-create:
+   ```
+   moved {
+     from = module.observability_agents[0].module.logs_agent[0].helm_release.logs_agent
+     to   = module.logs_agent[0].helm_release.logs_agent
+   }
+   ```
+- However since the helm chart being used in the new [terraform-ibm-monitoring-agent](https://github.com/terraform-ibm-modules/terraform-ibm-monitoring-agent) module is completly different to the helm chart used in this module, there is no way to do an update-in-place. Upgrading to this version will destroy the old helm release and create a new one so please plan accordingly before upgrading.
+---
+
 [![Graduated (Supported)](https://img.shields.io/badge/Status-Graduated%20(Supported)-brightgreen)](https://terraform-ibm-modules.github.io/documentation/#/badge-status)
 [![pre-commit](https://img.shields.io/badge/pre--commit-enabled-brightgreen?logo=pre-commit&logoColor=white)](https://github.com/pre-commit/pre-commit)
 [![latest release](https://img.shields.io/github/v/release/terraform-ibm-modules/terraform-ibm-observability-agents?logo=GitHub&sort=semver)](https://github.com/terraform-ibm-modules/terraform-ibm-observability-agents/releases/latest)