[HarfBuzz] problem with hb_ot_layout_lookup_would_substitute

[Werner LEMBERG]

>> Doh.  Thanks, it works now.  It's *really* time that HarfBuzz gets
>> documented :-)
> 
> That's definitely true.  But Werner, you being FreeType maintainer
> of over a decade, I don't agree with you this time.  *You* should
> know that a parameter called "glyphs" takes glyph indices, not
> Unicode characters...

Yep, my fault.  I was distracted by the `hb_codepoint_t' type.

> That said, I also want to add that the documentation infrastructure
> is fully in place and all that is missing is content.  Anyway can
> document a function or two and send a me patch / pull request.

If you open some cans full of time for me, I would immediately start
with that.  However, I think that you are the very person who should
add raw documentation (this is, adding one or two sentences to roughly
describe each function); other people like me could then polish that.
It's *not* fun to be forced to check the sources in case a function
parameter is not obvious – and the obviousness differs enormously
between you and me, since you are the author...


    Werner