Design column addition

[dbaderINO]

Column addition should be refined.

Ideas: Edit mode, hover with "+"-Button between columns, d&d, ...

[bitionaire]

The function to add a column should be placed much more prominently (user feedback).

[Resaki1]

Idea 1: When users are at the edge of the board, the nav buttons turn to a column addition button. Clicking this button adds a column to the left/right:

Idea 2: When hovering between column headers, a column addition button appears, which, when pressed, adds a column at that position:

Idea 3: A new option within the board settings dialog leads to a Edit Layout menu, where templates can be selected and columns can be added, deleted, renamed, moved, and made visible/hidden. In the future, it might be a good idea to save the current layout as a new template.

[SelinaBuff]

@Kraft16 the last pictures are showing a nice example of how we could do it for the template page when the user wants to create a new board.