kanban

Thanks for this brilliant app. I am currently self-hosting in docker.

Please allow users to copy a card, including tasks. I use templates so this would be very helpful.

Thanks again.

Describe the bug
Some translation are missing

• In tasks home page, "View task for other members" is not translated
  

• In tasks home page, "View task for other members" > "search" is not translated
  ![S7](https://user-images.githubusercontent.com/22451567/116979288-196c6

It would be nice to have a function to export the elements to JSON.
Using this it should be easier to send the elements to ajax for example.

I think it would be a good idea to add something like "bottom header". For example, I want to add a button to add a new card or some information