Add alias for staging tags.

gitconfig

@@ -13,6 +13,7 @@
   lg = log --graph --decorate --date=relative --abbrev-commit --pretty=format:'%Cred%h%Creset [%an]%C(yellow)%d%Creset %s %Cgreen(%ar)%Creset'
   recent = reflog -20 --date=relative
   pb = planbox
+  staging-tags = tag -l \"staging*\"
 [rerere]
   enabled = true
 [merge]
@@ -35,4 +36,3 @@
   prompt = false
 [gc]
   pruneExpire = "1 week ago"
-