During dicuss phase, anyone can add topic cards to actions column.

[zorn]

Currently, the Actions column is open to adding and editing topic cards during all phases. This should only be allowed during the discussion phase.

During a non-discuss phase, we should hide the Add button for that column and display a short message saying that actions can be made during the discussion phase.

Out of scope:

• There is some interest in maybe hiding the Actions column until the discussion phase, but for now that is off the table.