add jenkinsfile

In the `Build` stage, the site generated into `build` directory.
Also the `CNAME` file created in the same stage with `PROD_SITE`

Jenkinsfile

@@ -0,0 +1,61 @@
+pipeline {
+  agent { label 'linux' }
+
+  options {
+    disableConcurrentBuilds()
+    /* manage how many builds we keep */
+    buildDiscarder(logRotator(
+      numToKeepStr: '20',
+      daysToKeepStr: '30',
+    ))
+  }
+
+  environment {
+    GIT_COMMITTER_NAME = 'status-im-auto'
+    GIT_COMMITTER_EMAIL = 'auto@status.im'
+    PROD_SITE = 'waku.guide'
+    DEV_SITE  = 'dev.waku.guide'
+    DEV_HOST  = 'jenkins@node-01.do-ams3.sites.misc.statusim.net'
+    SCP_OPTS  = 'StrictHostKeyChecking=no'
+  }
+
+  stages {
+    stage('Install') {
+      steps {
+        sh "yarn install"
+      }
+    }
+
+    stage('Build') {
+      steps {
+        sh 'yarn build'
+        sh "echo ${env.PROD_SITE} > build/CNAME"
+      }
+    }
+
+    stage('Publish Prod') {
+      when { expression { env.GIT_BRANCH ==~ /.*master/ } }
+      steps {
+        sshagent(credentials: ['status-im-auto-ssh']) {
+          sh "ghp-import -p build"
+        }
+      }
+    }
+
+    stage('Publish Devel') {
+      when { expression { env.GIT_BRANCH ==~ /.*develop/ } }
+      steps {
+        sshagent(credentials: ['jenkins-ssh']) {
+          sh """
+            rsync -e 'ssh -o ${SCP_OPTS}' -r --delete build/. \
+              ${env.DEV_HOST}:/var/www/${env.DEV_SITE}/
+          """
+        }
+      }
+    }
+  }
+
+  post {
+    cleanup { cleanWs() }
+  }
+}