[Feature request] Option to disable the recurring icon

[Hund]

It would be nice to be able to optionally disable the ⟳ icon and replace it with some text, like [R]. Not all terminal emulators have support for characters like this. For me, it only shows as a square box.

[WhyNotHugo]

Sounds like a reasonable feature requires.

We can add a configuration setting (repeat-symbol = "⟳"). This needs to be passed to the serialiser when instantiated.

When aligning columns, we need to take care to use len(repeat_symbol).