init .config git tracking

config/fish/functions/grename.fish

@@ -0,0 +1,11 @@
+function grename -d "Rename 'old' branch to 'new', including in origin remote" -a old new
+  if test (count $argv) -ne 2
+    echo "Usage: "(status -u)" old_branch new_branch"
+    return 1
+  end
+  git branch -m $old $new
+  git push origin :$old
+  and git push --set-upstream origin $new
+end
+
+complete -c grename -x -a "(complete -C 'git branch ')"