Make it more discoverable to create requirements for a whole table

Currently, users have to select rows and type Alt + Shift + R, to get all requirements numbered automatically. We could improve:

• Show a hint in the column header,

• It only works with text selection, but Confluence tables have cell selection too. So make it work with it.

• Add the stuff in the leftmost cell that is selected, not just in the first cell of the row.

Implementation

Use the class .mceSelected.