add timetables page and translation

_includes/timetables.css

@@ -0,0 +1,35 @@
+.timetable {
+  border-spacing: 0;
+}
+.timetable td {
+  border-bottom: 1px solid black;
+  border-right: 1px solid black;
+  padding: 0.5em;
+}
+.timetable tr:not(:first-child) th {
+  border-right: 1px solid black;
+  border-left: 1px solid black;
+  position: sticky;
+  left: 0;
+  background: #fefefe;
+}
+.timetable th {
+  border-bottom: 1px solid black;
+}
+.timetable th:first-child {
+  position: sticky;
+  left: 0;
+  background: #fefefe;
+}
+.timetable tr {
+  position: relative;
+  height: 42px;
+}
+.timetable tr::after {
+  content: "";
+  position: absolute;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  border-bottom: 1px dotted rgba(0,0,0,0.5);
+}

content/de/first-steps.md

@@ -7,3 +7,5 @@ eleventyNavigation:
 ---
 # Erste Schritte
 
+## Stundenpläne
+Am Mittwoch findet die Einschreibung in die Seminargruppen, und damit in einen Stundenplan, statt. Alle Infos dazu gibt es hier: [Stundenpläne](/timetables/).

content/en/first-steps.md

@@ -7,3 +7,5 @@ eleventyNavigation:
 ---
 # First Steps
 
+## Timetables
+On Wednesday, the enrollment in the seminar groups, and thus in a timetable, takes place. You can find all relevant information here: [timetables](/timetables/).