Initial README.md update and adding MAINTAINERS.md after repository owner change (#1014)

Signed-off-by: Sebastian Schuster <[email protected]>

Author: sschu

MAINTAINERS.md

@@ -0,0 +1,9 @@
+# Active maintainers
+
+* [Sebastian Schuster](https://github.com/sschu)
+* [Thomas Darimont](https://github.com/thomasdarimont)
+
+# Emeritus maintainers
+
+* [Michael Parker](https://github.com/mrparkers)
+

README.md

@@ -1,6 +1,9 @@
 # terraform-provider-keycloak
 Terraform provider for [Keycloak](https://www.keycloak.org/).
 
+[!NOTE]
+Please note that this is currently work-in-progress, please be patient while we are preparing for the first release in the new organization.
+
 ## Docs
 
 All documentation for this provider can now be found on the Terraform Registry: https://registry.terraform.io/providers/mrparkers/keycloak/latest/docs
@@ -92,6 +95,11 @@ KEYCLOAK_URL="http://localhost:8080" \
 make testacc
 ```
 
+## Acknowledgments
+
+The Keycloak Terraform Provider was originally created by [Michael Parker](https://github.com/mrparkers). Many thanks for the hard work and dedication in building the foundation for this project.
+Also, many thanks to all the contributors extending it and approving the license change to maintain it as part of the [Keycloak](https://www.keycloak.org/) project.
+
 ## License
 
 This software is licensed under Apache License, Version 2.0, (LICENSE-APACHE-2.0 or https://www.apache.org/licenses/LICENSE-2.0)