Test build with jenkins

Jenkinsfile

@@ -1,9 +1,11 @@
 pipeline {
-    agent any
+    agent {
+        docker { image 'docker:dind' }
+    }
     stages {
         stage('Build') {
             steps {
-                echo 'Building'
+                sh 'docker build -t docs:latest .'
             }
         }
     }