add MS lab link

Author: vladak

docs/unix-access.html

@@ -21,8 +21,9 @@
 
 <h1>Access to Unix machines at MFF UK</h1>
 
-<p>You can remotely use some Linux machines in the labs of Mal&aacute;
-Strana.  Those are <code>u-pl1.ms.mff.cuni.cz</code> to
+<p>You can remotely use some Linux machines in the
+<a href="https://www.ms.mff.cuni.cz/labs/index.html.en">labs of Mal&aacute;
+Strana</a>.  Those are <code>u-pl1.ms.mff.cuni.cz</code> to
 <code>u-pl37</code>, as of writing this.  Use the <code>ssh</code> client
 shipped with your Unix/Linux/Mac installation to reach those machines, for
 example: