Add a git alias "git amend".

This allows us to generate a new git commit hash without changing the commit contents which is useful for triggering CI workflows.

ansible/roles/base/files/gitconfig_home

@@ -7,6 +7,7 @@
 [alias]
 	lg = log --color --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit
 	bh = log --oneline --branches=* --remotes=* --graph --decorate
+	amend = commit --amend --no-edit
 [core]
 	excludesfile = ~/.gitignore_global
 [commit]