Add a picture of a lynx (#22)

Co-authored-by: Laurenz <laurmaedje@gmail.com>

Author: omentic

NOTICE

@@ -107,7 +107,7 @@ The SIL Open Font License Version 1.1 applies to:
   with Reserved Font Name Asana Math.
   Copyright (c) 2000 Young Ryu,
   with Reserved Font Name pxfonts.
-  Copyright (c) 1997, 1999 Claudio Beccari, 
+  Copyright (c) 1997, 1999 Claudio Beccari,
   with Reserved Font Name gsmn1000.
 
 * Pennstander fonts in files/fonts/Pennstander*.otf
@@ -998,18 +998,18 @@ The GUST Font License applies to:
 % This work may be distributed and/or modified under the conditions
 % of the LaTeX Project Public License, either version 1.3c of this
 % license or (at your option) any later version.
-% 
+%
 % Please also observe the following clause:
 % 1) it is requested, but not legally required, that derived works be
 %    distributed only after changing the names of the fonts comprising this
 %    work and given in an accompanying "manifest", and that the
 %    files comprising the Work, as listed in the manifest, also be given
 %    new names. Any exceptions to this request are also given in the
 %    manifest.
-%    
+%
 %    We recommend the manifest be given in a separate file named
 %    MANIFEST-<fontid>.txt, where <fontid> is some unique identification
-%    of the font family. If a separate "readme" file accompanies the Work, 
+%    of the font family. If a separate "readme" file accompanies the Work,
 %    we recommend a name of the form README-<fontid>.txt.
 %
 % The latest version of the LaTeX Project Public License is in
@@ -1686,3 +1686,22 @@ dealings in these Data Files or Software without prior written
 authorization of the copyright holder.
 
 ================================================================================
+
+================================================================================
+The Unsplash License applies to:
+
+* "A lynx standing in the middle of a forest" in files/images/lynx.jpg
+  Copyright 2024 Pascal Bullan (@jetztabertempo)
+  Via Unsplash
+  (https://unsplash.com/photos/a-lynx-standing-in-the-middle-of-a-forest-6njkAeHHMOE)
+
+The Unsplash License
+
+Unsplash grants you an irrevocable, nonexclusive, worldwide copyright license
+to download, copy, modify, distribute, perform, and use images from Unsplash for
+free, including for commercial purposes, without permission from or attributing
+the photographer or Unsplash. This license does not include the right to compile
+images from Unsplash to replicate a similar or competing service.
+
+URL: https://unsplash.com/license
+================================================================================

files/images/lynx.jpg

@@ -165,6 +165,7 @@ files! {
     "images/heron.jpg",
     "images/linked.svg",
     "images/logo.svg",
+    "images/lynx.jpg",
     "images/matplotlib.pdf",
     "images/molecular.jpg",
     "images/monkey.svg",