talksapp: update maintainer to Dmitri on index page

Francesc is no longer actively maintaining this project.

Also improve the GitHub issue tracker link to prepopulate
the "talksapp: " issue title prefix.

Change-Id: Id3b337039734e59c792310796b3facbd979d7909
Reviewed-on: https://go-review.googlesource.com/c/140677
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Tuo Shan <shantuo@google.com>
Reviewed-by: Francesc Campoy Flores <campoy@golang.org>
1 file changed