add missing doc about jenkins

DOCUMENTATION/content/documentation/index.md

@@ -431,15 +431,35 @@ To learn more about how Docker publishes ports, please read [this excellent post
 
 
 
-
 <br>
-<a name="Laravel"></a>
+<a name="Use-Jenkins"></a>
+## Use Jenkins
+
+1) Boot the container `docker-compose exec jenkins bash`
+
+2) Go to `http://localhost:8090/` (if you didn't chanhed your default port mapping) 
+
+3) Authenticate:
+
+- Default username is `admin`.
+- Default password is `docker-compose exec jenkins cat /var/jenkins_home/secrets/initialAdminPassword`. 
+
+(To enter container as root type `docker-compose exec --user root jenkins bash`).
+
+4) Install some plugins.
 
+5) Create your first Admin user, or continue as Admin.
 
+Note: to add user go to `http://localhost:8090/securityRealm/addUser` and to restart it from the web app visit `http://localhost:8090/restart`.
 
+You may wanna change the default security configuration, so go to `http://localhost:8090/configureSecurity/` under Authorization and choosing "Anyone can do anything" or "Project-based Matrix Authorization Strategy" or anything else.
 
 
 
+
+<br>
+<a name="Laravel"></a>
+
 <a name="Install-Laravel"></a>
 ## Install Laravel from a Docker Container
 
@@ -1074,9 +1094,6 @@ To change the default forwarded port for ssh:
 
 
 
-
-
-
 <br>
 <a name="Change-the-MySQL-Version"></a>
 ## Change the (MySQL) Version