Added a warning when opening the merge dialog on a sheet that has not been
configured.
Version 12: 2022-11-14
Fixed problem that prevented the instruction card from showing in the sidebar.
There will no longer be a Mergery entry in the Extensions menu.
Version 11: 2022-11-11
Additional error check - spreadsheet with no tags.
Version 10: 2022-09-11
All duplicate emails will be removed. If an email in the cc list also exists in the to list, it will be removed from the cc list.
If an email in the bcc list also exists in the to list or the cc list, it will be removed from the bcc list.