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/she-hangs-her-head-sad-lisa.tex

@@ -0,0 +1,36 @@
+\begin{song}{
+  title = {She hangs her head (Sad Lisa)},
+  lyrics = {Cat Stevens},
+  composer = {Cat Stevens},
+  cl = 285,
+  libock = 300,
+}
+
+\begin{verse}
+She ha \chord{e}ngs her head and cries in my shirt. \\
+She mus \chord{D}t be hur \chord{e}t very bad \chord{D}l \chord{G}y. / Tell me, what´s \\
+ma \chord{D}king you sad \chord{e}ly \chord{A}? / Ope \chord{e}n your door, d \chord{A}on´t \\
+h \chord{D}ide in the d \chord{C}ark, / you´re \chord{D}lost in the d \chord{e}ark, you \\
+can t \chord{D}rust m \chord{G}e, / cause you know that h \chord{D}ow it \\
+mu \chord{e}st \chord{A} be. / L \chord{e}isa, Lis \chord{D}a, \chord{C} s \chord{H7}ad Lisa, Lisa \chord{e}.
+\end{verse}
+
+\begin{verse}
+Her eyes like windows shiding in rain, \\
+upon her pain getting deeper. \\
+So my love wants to relieve her, \\
+she walks alone from world to world, \\
+lost in the hall, she can tear me. \\
+So I know she likes to be near me. / Lisa...
+\end{verse}
+
+\begin{verse}
+She sits in a corner by the door. \\
+There must be more I can tell her. \\
+If she really wants me to help her, \\
+I do what I can to show her the way. \\
+And may be one day I will free her, \\
+so I know no one can see her. / Lisa…
+\end{verse}
+
+\end{song}