Add short example signature config to pacman.conf

This is similar to what we do with every other option.

Signed-off-by: Dan McGee <dan@archlinux.org>

etc/pacman.conf.in

@@ -36,6 +36,9 @@ Architecture = auto
 #CheckSpace
 #VerbosePkgLists
 
+# PGP signature checking
+#SigLevel = Optional
+
 #
 # REPOSITORIES
 #   - can be defined here or included from another file
@@ -60,6 +63,7 @@ Architecture = auto
 # servers immediately after the header and they will be used before the
 # default mirrors.
 #[core]
+#SigLevel = Required
 #Server = ftp://ftp.example.com/foobar/$repo/os/$arch/
 # The file referenced here should contain a list of 'Server = ' lines.
 #Include = @sysconfdir@/pacman.d/mirrorlist
@@ -67,5 +71,6 @@ Architecture = auto
 # An example of a custom package repository.  See the pacman manpage for
 # tips on creating your own repositories.
 #[custom]
+#SigLevel = Optional TrustAll
 #Server = file:///home/custompkgs