Mention the mailing list.

Author: janpgit

docs/exams.html

@@ -30,13 +30,11 @@ <h3>Prerequisites</h3>
 
 <h3>Dates</h3>
 
-<p>
-The dates of exams will be in the information system.
-<b>
-Be sure to check any updates in the information system in the News section
-the day before the exam.
-</b>
-There will be sufficient number of dates.
+<p>The dates of exams will be in the information system.  There will be
+sufficient number of dates.  If there are any last minute changes, those will be
+announced on nswi015-l@mff.cuni.cz.  See the <a
+href="https://devnull-cz.github.io/unix-linux-prog-in-c/">main page</a> on how
+to subscribe to the mailing list.
 </p>
 
 <h3>Tools</h3>