hdp page update based on Gaetan suggestions

portfolio-nuxt/pages/a_history_of_the_domino_problem.vue

@@ -130,7 +130,7 @@
                     <br>
                     performance by KALI ENSEMBLE 
                     <br>
-                    23 Nov 2023 | Doors 20 Uhr - Concert 20:30 Uhr
+                    23 Nov 2023 | 20:30 Uhr (Doors open at 20:00 Uhr)
                     <br>
                     <NuxtLink to='https://www.km28.de/'>KM28</NuxtLink>
                     <br>