update jupyterhub page, include advanced form instructions

doc.zih.tu-dresden.de/docs/access/jupyterhub.md

@@ -35,9 +35,6 @@ Old taurus
 
 At login page please use your ZIH credential (without @tu-dresden.de).
 
-For example:
-Username: ddde223z
-
 ![Simple form](misc/jupyterhub_loginpage.png)
 {: align="center"}
 
@@ -67,6 +64,14 @@ We have created three profiles for each Cluster, namely:
 | VIS - 2 Core, 4GB, 2 Hours                   | Visualization   | ANSYS                     |
 | VIS - 4 Core, 8GB, 6 Hours                   | Visualization   | ANSYS                     |
 
+### Advanced options
+
+Aside of the standard profiles there is the possibility to specify custom parameters to the job
+spawner. This can be activate clicking at the advanced button located below to the profile list.
+
+![Advanced form](misc/jupyterhub_advanced_form.png)
+{: align="center"}
+
 ## JupyterLab
 
 After your session it is spawned you will be redirected to JupyterLab. The main interface looks
@@ -107,7 +112,14 @@ At the following table it's possible to see what is available at each cluster.
 In JupyterHub, you can create scripts in notebooks. Notebooks are programs which are split into
 multiple logical code blocks. Each block can be executed individually. In between those code
 blocks, you can insert text blocks for documentation. Each notebook is paired with a kernel running
-the code. We currently offer one for Python, C++, MATLAB and R.
+the code.
+
+We offer some custom kernel for Julia*, MATLAB and R.
+
+!!! note
+    Some kernels may not be available depending of the amounting of resources requested for the
+    job or due to the availability of modules to an specific cluster.
+
 
 ### Version Control of Jupyter Notebooks with Git