Merge branch 'jk/push-force-with-lease-creation' into maint

Merge branch 'jk/push-force-with-lease-creation' into maint

"git push --force-with-lease" already had enough logic to allow
ensuring that such a push results in creation of a ref (i.e. the
receiving end did not have another push from sideways that would be
discarded by our force-pushing), but didn't expose this possibility
to the users.  It does so now.

* jk/push-force-with-lease-creation:
  t5533: make it pass on case-sensitive filesystems
  push: allow pushing new branches with --force-with-lease
  push: add shorthand for --force-with-lease branch creation
  Documentation/git-push: fix placeholder formatting