Change confusing language in guide

HPC_Python_Guide.md

@@ -57,13 +57,13 @@ a100sh
 
 1. Open a terminal (Applications->Terminal Emulator).
 
-2. If you want GPU, we need to enable X11 forwarding, by adding the -X option.
-   Enter one of the following (see https://www.hpc.dtu.dk/?page_id=2129):
+2. If you want GPU, enter one of the following (see https://www.hpc.dtu.dk/?page_id=2129):
    ```
    voltash -X
    sxm2sh -X
    a100sh -X
    ```
+   Remeber the `-X` which enables X11 forwarding! It is needed to open a browser for the notebook.
 
 3. Navigate to your project folder and activate the virtualenv. Same steps as in [section II](#ii-setup-virtualenv).