Add Jenkinsfile.

Jenkinsfile

@@ -0,0 +1,21 @@
+node("linux && amd64 && docker") {
+  docker.image("icedream/freetz@sha256:6607702228ee9ee819d888702acf3ddefe7609132f7f15c88349251a15f5a5cc").inside {
+    dir("config-workspace") {
+      checkout scm
+
+      sh """
+      cd ${pwd()}
+      chown -R freetz:freetz .
+      cp -rv . /freetz
+      """
+    }
+
+    dir("/freetz") {
+      sh """
+      cd ${pwd()}
+      su freetz -c \"sh -c 'umask 0022 && make oldconfig && make'\"
+      """
+      archive "images/**,outboard/**"
+    }
+  }
+}