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 <[email protected]>
Reviewed-by: Tuo Shan <[email protected]>
Reviewed-by: Francesc Campoy Flores <[email protected]>

Author: dmitshur

talksapp/assets/home.article

@@ -1,14 +1,14 @@
 talks.godoc.org
 
-Francesc Campoy (maintainer)
-@francesc
+Dmitri Shuralyov (maintainer)
+@dmitshur
 
 Gary Burd
 @gburd
 
 * Introduction
 
-This site plays slide presentations and articles stored on GitHub in the 
+This site plays slide presentations and articles stored on GitHub in the
 [[https://godoc.org/golang.org/x/tools/present][present format]].
 
 The syntax for URLs is:
@@ -24,4 +24,4 @@ This page is [[/github.com/golang/gddo/talksapp/assets/home.article][an article]
 
 * Feedback
 
-Report bugs and request features using the [[https://github.com/golang/gddo/issues/new][GitHub Issue Tracker]]. 
+Report bugs and request features using the [[https://github.com/golang/gddo/issues/new?title=talksapp%3A+][GitHub Issue Tracker]].