🐛 Adding key to Tiptap component in template

[mseiimeorn]

fixes issue #51 Fixes the checkboxes being synched across multiple days. As it is only affecting the UI but not the actual value, it might actually rather be an issue with Tiptap, though I don't know if it would maybe be fixed with some newer version of Tiptap. So adding a key would refresh the UI when changing the day

You can test it by adding 2 checkbox on 2 different days, check one and test whether the other day was updated or not.