Bug#424879: developers-reference: Document best practise for update-alternatives

[Kurt Roeckx <kurt@roeckx.be>]

Package: developers-reference
Version: 3.8.8

Hi,

It seems that the usage of update-alternatives in postinst/prerm 
is underdocumented.

Policy does mention update-alternatives but just points to the
update-alternatives manpage.  That itself just says that it's
"usually called from the postinst or prerm scripts".

I think it would be good that there was better documentation for it on
how to use it in the maintainer scripts.  During which part of the
script it should do what, and things like that.

I'm not sure what the best place to document this is, but the
developers-reference seems to be a good place to me.


Kurt