Add archive note

Author: bp-alex

README.md

@@ -1,3 +1,8 @@
+# THIS PROJECT IS ARCHIVED
+
+**Cross compilation is now performed in the
+[LmdbJava](https://github.com/lmdbjava/lmdbjava) project.**
+
 [![Maven Build and Deployment](https://github.com/lmdbjava/native/workflows/Maven%20Build%20and%20Deployment/badge.svg)](https://github.com/lmdbjava/native/actions)
 [![Maven Central](https://img.shields.io/maven-central/v/org.lmdbjava/lmdbjava-native-parent.svg?maxAge=3600)](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22org.lmdbjava%22%20AND%20a%3A%22lmdbjava-native-parent%22)
 [![License](https://img.shields.io/badge/license-OpenLDAP-blue.svg?maxAge=2592000)](http://www.openldap.org/software/release/license.html)