add a button to suggest random tag pill colors

[beesinblenders]

In one of my use cases, I use a lot of tags and they help me visualize patterns at the scale of the board. This leads me to create specific colors for every one of them.

It would be a great help and save me a lot of time if there was a button to randomize the background and foreground colors, instead of always the same colors that I have to change manually – my only requirement being that they be all different, I don't care what color they are.

This goes the same way as FR#19 (More visual distinction), but it's not strictly the same use (tags allow for several colors on a same card).

That being said, thank you for a beautiful and very useful plug-in.