compile timetable from scratch each time

.latexmkrc

@@ -1,2 +1,46 @@
-$pdf_mode = 4;        # LuaLaTeX
+@default_files = ('timetable/zeitplan.tex', 'manual.tex');
-@default_files = ('manual.tex');
+
+# descriptions stolen from https://collaborating.tuhh.de/alex/latex-git-cookbook/-/blob/4174942b6674588d016189c708327dccbaac5b8d/.latexmkrc
+
+# ======================================================================================
+# PDF Generation/Building/Compilation
+# ======================================================================================
+
+# PDF-generating modes are:
+# 1: pdflatex, as specified by $pdflatex variable (still largely in use)
+# 2: postscript conversion, as specified by the $ps2pdf variable (useless)
+# 3: dvi conversion, as specified by the $dvipdf variable (useless)
+# 4: lualatex, as specified by the $lualatex variable (best)
+# 5: xelatex, as specified by the $xelatex variable (second best)
+$pdf_mode = 4;
+
+# Treat undefined references and citations as well as multiply defined references as
+# ERRORS instead of WARNINGS.
+# This is only checked in the *last* run, since naturally, there are undefined references
+# in initial runs.
+# This setting is potentially annoying when debugging/editing, but highly desirable
+# in the CI pipeline, where such a warning should result in a failed pipeline, since the
+# final document is incomplete/corrupted.
+#
+# However, I could not eradicate all warnings, so that `latexmk` currently fails with
+# this option enabled.
+# Specifically, `microtype` fails together with `fontawesome`/`fontawesome5`, see:
+# https://tex.stackexchange.com/a/547514/120853
+# The fix in that answer did not help.
+# Setting `verbose=silent` to mute `microtype` warnings did not work.
+# Switching between `fontawesome` and `fontawesome5` did not help.
+$warnings_as_errors = 0;
+
+# Show used CPU time. Looks like: https://tex.stackexchange.com/a/312224/120853
+$show_time = 1;
+
+# Default is 5; we seem to need more owed to the complexity of the document.
+# Actual documents probably don't need this many since they won't use all features,
+# plus won't be compiling from cold each time.
+$max_repeat=5;
+
+# Whether to change working directory to the directory specified for the main source
+# file before processing it.  The default behavior is not to do this, which is the same
+# as the behavior of *latex programs.  This variable is set by the -cd and -cd- options
+# on latexmk's command line.
+$do_cd = 1;