docs: mathpartir is part of TeXLive nowadays

docs/setup.tex

@@ -14,7 +14,7 @@
 \usepackage{amssymb}
 \usepackage{stmaryrd}
 
-\usepackage{\basedir mathpartir}
+\usepackage{mathpartir}
 
 \usepackage{\basedir pftools}
 \usepackage{\basedir iris}