Add optional tiles border on exported PDF

[RodriSanchez1]

An user report:

If possible, it could be very helpful to have borders for tiles (buttons and folders), especially for tiles with a white background as when Boards are exported as a PDF there are no visible borders compared to what you could see if the tiles had a different background colour.

For printable Communication Choice Boards, it can be quite common to have borders for different choices (tiles). This can help differentiate the choices and assist the communicator with selecting the choices they would like to.

[AvitalHass]

@RodriSanchez1 i'm working on this one, i added a black border to the tiles, like that:

what do you think? LMK if you want to change something or not, if not i'll push my change.

[AbbasReads]

Hi! I'm new to open source. I'd like to work on this. Please let me know if this issue is still on.

[muhammadali-se]

hey @RodriSanchez1 @tomivm
I'm interested to fix this issue can you please assign me if it's already not fixed