Add option to show end of context

[ChHaeni]

Hi,
first of all, thanks a lot for this awesome plugin!

I'm heavily using/relying on the relative numbers of the context and sometimes I'd find it really helpfull if I had the relative numbers to the contexts end, too. It would be awesome, if the plugin would have an option to enable showing the end of the current context.

Feel free to close this issue, if it means too much effort for little gain...

[lewis6991]

This would be useful for do { } while(); loops where the condition is at the bottom. It would also make it easy to know where the context ends via the line numbers. Such context could just show at the bottom (difficult), or we could just show it as the top as do { ... } while(); (easier).