Add git alias pr for pull request

scripts/git-config.sh

@@ -121,8 +121,8 @@ git_alias copy 'branch --copy'
 git_alias co checkout
 git_alias cob "checkout -b"
 git_alias sw switch
-# https://docs.gitlab.com/ee/user/project/merge_requests/reviews/index.html#checkout-merge-requests-locally-through-the-head-ref
 git_alias mr $'!sh -c \'git fetch $1 merge-requests/$2/head:mr-$1-$2 && git checkout mr-$1-$2\' -'
+git_alias pr $'!sh -c \'git fetch $1 pull/$2/head:pr-$1-$2 && git checkout pr-$1-$2\' -'
 
 git_alias ci commit
 git_alias cif "commit --fixup"