add Jenkinsfile

Jenkinsfile

@@ -0,0 +1,17 @@
+pipeline {
+    agent any
+
+    stages {
+        stage('phpstan') {
+            steps {
+                sh """
+                docker run --pull=always \
+						-v ${env.WORKSPACE}:/src/tt-rss/plugins/plugin \
+						--workdir /src/tt-rss \
+						--rm cthulhoo/ttrss-fpm-pgsql-static:latest \
+						php81 ./vendor/bin/phpstan analyse plugins/plugin
+                """
+            }
+        }
+    }
+}