Close the `<h3>` header tag with a closing `</h3>` tag to fix the HTML
syntax.
Change-Id: Ic86c5f31ec5550d6875aa085eed8da6a75881405
Reviewed-on: https://go-review.googlesource.com/2104
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This change allows the directory front page to be more easily configurable.
Templates are now read only at start-up and stored in a map rather than re-parsed for each page rendering.
LGTM=adg
R=adg
CC=golang-codereviews
https://golang.org/cl/109080044