texlive/pkgs.nix: add revision

pkgs/tools/typesetting/tex/texlive/tl2nix.sed

@@ -8,6 +8,9 @@ $a}
 # quote package names, as some start with a number :-/
 s/^name (.*)/name "\1"/
 
+# extract revision
+s/^revision ([0-9]*)$/  revision = \1;/p
+
 # form an attrmap per package
 /^name /s/^name (.*)/\1 = {/p
 /^$/,1i};