Update "command line" lecture

The only problem with this lecture that I can remember is the general problem with Windows users

We could either try to get our hands on a Windows machine before the lecture and try to come up with a recommendation on how to connect to Levante, or hope that no Windows users will show up

lectures/command-line/slides.qmd

@@ -31,7 +31,7 @@ subtitle: "Controlling local and remote machines"
   ```{.sh}
   vim test.txt
   ```
-* Basic usage: hit {{< kbd i >}} to activate _insert_ mode. Type something and hit {{< kbd Esc >}} to fall back into _normal_ mode. Save and close the file using {{< kbd :wq >}}.
+* Basic `vim` usage: hit {{< kbd i >}} to activate _insert_ mode. Type something and hit {{< kbd Esc >}} to fall back into _normal_ mode. Save and close the file using {{< kbd :wq >}}.
 
 ## Scripts
 
@@ -90,7 +90,7 @@ Different ways to work on a cluster depending on the task:
 
 * Housekeeping/compiling (login nodes)
 * Interactive sessions (compute nodes, `salloc`)
-* Batch scriptsscripts (compute nodes, `sbatch`)
+* Batch scripts (compute nodes, `sbatch`)
 * External services (e.g. _Jupyterhub_)
 
 ## SSH
@@ -217,7 +217,7 @@ Different ways to work on a cluster depending on the task:
 forward graphical user interfaces (GUIs) from the server
 
 * Install an X-server on your local machine (e.g. XQuartz)
-* Pass the `-X` option to your `ssh` command^[or check the SSH config option]
+* Pass the `-X`^[Mac users might want to use `-Y`, or MacOS will quit the forwarding after about 20 min.] option to your `ssh` command^[or check the SSH config option]
   ```{raw}
   ssh -X levante
   ```