2 feature request

Hello,

thanks for the nice extension.

I would like to request 2 features.

- move tab groups (UP/DOWN)
   to better sort the groups


- create a new tab group
  i got several groups i which i want to split to sort them better, so it would be nice if there would be an option to create a new (empty) tab group where i could move then the tabs into

Thank you very much