gendoc: do not strip 'hg ' from synopsis

This was an old left-over from when the synopsis line was used as a
header. We now have the command name by itself as the header and the
synopsis as a literal block immediately after..

doc/gendoc.py

@@ -135,7 +135,7 b' def commandprinter(ui, cmdtable, section'
         for line in synopsislines:
             # some commands (such as rebase) have a multi-line
             # synopsis
-            ui.write("   %s\n" % line.replace("hg ","", 1))
+            ui.write("   %s\n" % line)
         ui.write('\n')
         # description
         ui.write("%s\n\n" % d['desc'][1])