Doc: Add wiki link

- closes https://github.com/assimp/assimp/issues/5240

test/models-nonbsd/IFC/linklist.txt

@@ -1,4 +1,4 @@
 Good IFC test cases
 ===================
 
-http://www.iai.fzk.de/www-extern/index.php?id=1135
+https://www.ifcwiki.org/index.php/Examples