Info message "Using `main2` palette as only two colours are required."

[Olivia-Box-Power]

If you need two colours in a categorical palette, scale_colour/fill_discrete_af currently returns the info message "Using main2 palette as only two colours are required.". This could potentially be annoying if you produce a lot of charts and might be confusing for new users.

Options include

1. Leave info message as is

2. Have a package option with verbose = FALSE to allow users to switch off the message

3. Update the function documentation to make it clear when the main2 palette will be used.

[Olivia-Box-Power]

This issue may be fixed as part of #49