Since perl scripts (.pl) was already supported, add .pm for perl modules
#\r
# SPACE-DELIMITED\r
# SINCE 0.5.0\r
-web.prettyPrintExtensions = aea agc basic c cbm cl clj cpp cs css dart el erl erlang frm fs go groovy hs htm html java js latex lisp ll llvm lsp lua ml moxie mumps n nemerle pascal php pl prefs properties proto py r R rb rd Rd rkt s S scala scm sh Splus sql ss tcl tex vb vbs vhd vhdl wiki xml xq xquery yaml yml ymlapollo\r
+web.prettyPrintExtensions = aea agc basic c cbm cl clj cpp cs css dart el erl erlang frm fs go groovy hs htm html java js latex lisp ll llvm lsp lua ml moxie mumps n nemerle pascal php pl pm prefs properties proto py r R rb rd Rd rkt s S scala scm sh Splus sql ss tcl tex vb vbs vhd vhdl wiki xml xq xquery yaml yml ymlapollo\r
\r
# Registered extensions for markdown transformation\r
#\r