[petsc-dev] please make better manual pages

[Barry Smith]

   This manual page helps the user in no way understanding what a VecTagger is or is used for.  We can't read your mind, put at least a couple of sentences explaining that this thing is please.

   
  VecTaggerCreate - create a Vec tagger context

   Not Collective

   Input Arguments:
.  comm - communicator on which the vec tagger will operate

   Output Arguments:
.  tagger - new Vec tagger context

   Level: advanced