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/leave-her-johnny.tex

@@ -0,0 +1,65 @@
+\begin{song}{
+  title = {Leave her, Johnny},
+  libock = 282,
+}
+
+\begin{verse}
+\chord{A}Oh, I thought I heard the old Man say: \\
+„ \chord{E}Leave her, Johnny, l \chord{A}eave her.“ \\
+Tom \chord{D}orrow y \chord{A}ou will \chord{h}get your p \chord{A}ay. \\
+And it‘s ti \chord{A}me for \chord{E}us to l \chord{A}eave her.
+\end{verse}
+
+\begin{verse}
+Ref.: \chord{E}Leave her, Johnny, l \chord{A}eave her! \\
+Oh, l \chord{D}eave her, Johnny, l \chord{A}eave her! \\
+For the \chord{D}voyage is lo \chord{A}ng and the w \chord{h}inds don‘t bl \chord{A}ow \\
+And it‘s t \chord{A}ime for \chord{E}us to le \chord{A}ave her.
+\end{verse}
+
+\begin{verse}
+Oh the skipper was bad, but the mate was worse. \\
+„Leave her, Johnny, leave her!“ \\
+He would cut down with a spike or a course. \\
+And it‘s time for us to leave her.
+\end{verse}
+
+\begin{verse}
+Oh, the wind was foul and the sea ran high. \\
+"Leave her, Johnny, leave her!" \\
+She shipped it green and none went by. \\
+And it's time for us to leave her.
+\end{verse}
+
+\begin{verse}
+I hate to sail on this rotten tub. \\
+"Leave her, Johnny, leave her!" \\
+No grog allowed and rotten grub. \\
+And it's time for us to leave her.
+\end{verse}
+
+\begin{verse}
+Now pull you lubbers, or you‘ll get no pay. \\
+„Leave her, Johnny, leave her.“ \\
+Oh pull you lubbers and then belay. \\
+And it's time for us to leave her.
+\end{verse}
+
+\begin{verse}
+We swore by rote for want of more. \\
+"Leave her, Johnny, leave her!" \\
+But now we're through so we'll go on shore. \\
+And it's time for us to leave her.
+\end{verse}
+
+\begin{verse}
+Worte und Weise: \\
+traditional Sea Shanty
+\end{verse}
+
+\begin{verse}
+Altes Walfangschiff, Illustration \\
+von Christiane Wegner-Klafszky
+\end{verse}
+
+\end{song}