Import 294 songs from Carmina Leonis PDF

Add import-songs.py script that extracts songs from the PDF text
and generates .tex files with leadsheets format. Adds song
properties for all reference books (BuLiBu, BuLiBuII, CL, SwA,
Barde, LiBock). Generates all-songs.tex with alphabetical inputs.

Note: Chord alignment is approximate from PDF extraction and
may need manual review for some songs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

songs/bruder-nun-wird-es-abend.tex

@@ -0,0 +1,42 @@
+\begin{song}{
+  title = {Bruder, nun wird es Abend},
+  lyrics = {olka (Erich Scholz)},
+  composer = {olka (Erich Scholz)},
+  bulibu = 386,
+  cl = 49,
+  swa = 26,
+  barde = 39,
+  libock = 42,
+}
+
+\begin{verse}
+Bru \chord{a}der, nun wird es \chord{E}Abend, \\
+ni \chord{a}mm dir ein Glas zum Wei \chord{E}n. \\
+/: Sc \chord{G}he \chord{G7}nke \chord{C} Triodimali, T \chord{a}riodimali, T \chord{F}riodimali \chord{a}ein :/
+\end{verse}
+
+\begin{verse}
+Stopf dir die lange Pfeife, \\
+denke nicht viel dabei. \\
+/: Singe Triodimali, Triodimali, Triodimali zwei. :/
+\end{verse}
+
+\begin{verse}
+Nichts will das Lied bedeuten, \\
+als etwas glücklich sein. \\
+/: Dreimal Triodimali, Triodimali, Triodimali drei. :/
+\end{verse}
+
+\begin{verse}
+Mondlampe lacht am Fenster, \\
+Schlaf klopft an die Tür. \\
+/: Leise Triodimali, Triodimali, Triodimali vier. :/
+\end{verse}
+
+\begin{verse}
+Traumschwere Worte fallen, \\
+Stille besiegt das Haus. \\
+/: Trinke Triodimali, Triodimali, Triodimali aus. :/
+\end{verse}
+
+\end{song}