The default header value can be a plus icon and the background colour of the column can be faded a bit. Clicking the plus icon should let you type in the column name (similar to if you were renaming the column). When you hit enter or blur, it should create the column.
The default header value can be a plus icon and the background colour of the column can be faded a bit. Clicking the plus icon should let you type in the column name (similar to if you were renaming the column). When you hit enter or blur, it should create the column.