[tex-eplain] Minor indexing gotcha.

[Karl Berry]

    Eplain knows about multiple indexes. Makeindex does not. 

Are you saying we should improve the documentation?

Incidentally, being the indexing maven you are, have you looked at
xindy?  (It's in TL'08.  Don't bother compiling it yourself unless you
are a glutton for punishment.)  I don't know if it behaves any better in
this respect, but at least it is being actively maintained, which is
more than I can say for makeindex.

Best,
karl