hdp page update based on Gaetan suggestions

portfolio-nuxt/pages/a_history_of_the_domino_problem.vue

@@ -114,7 +114,7 @@
                     Lichthof Ost, HU Berlin Hauptgebäude, Campus Mitte, Unter den Linden 6 (U-Bahn Unter den Linden oder Museuminsel)
                 </div>
                 <div class="mb-5">
-                    <span class="font-bold">Public lecture + Concert (free entrance) - 22 Nov 2023 | 19:30 Uhr</span>
+                    <span class="font-bold">Public lecture + Concert (free entrance) - 22 Nov 2023 | 19:30 Uhr (doors open at 19:00 Uhr)</span>
                     <br>
                     with Prof. JARKKO KARI (Turku University), moderated by Prof. Dr. GAËTAN BOROT (HU Berlin)
                     <br>