Merge branch 'docs-zj-hooks-update' into 'master'

Symlinked hooks aren't executed

See merge request gitlab-org/gitlab-ce!22933

doc/administration/custom_hooks.md

@@ -60,7 +60,7 @@ installations, this can be set in `gitlab-shell/config.yml`.
 
 The hooks are searched and executed in this order:
 
-1. `<project>.git/hooks/` - symlink to `gitlab-shell/hooks` global dir
+1. `gitlab-shell/hooks` directory as known to Gitaly
 1. `<project>.git/hooks/<hook_name>` -  executed by `git` itself, this is `gitlab-shell/hooks/<hook_name>`
 1. `<project>.git/custom_hooks/<hook_name>` - per project hook (this is already existing behavior)
 1. `<project>.git/custom_hooks/<hook_name>.d/*` - per project hooks