Add support for SigmaTau performance metrics in the evidence

[eldraco]

Please Describe The Feature You Want
To add the text (and maybe format) of sigmatau to evidence, so to have the performance metrics.

https://github.com/priamai/sigmatau

[Sar-thak-3]

Hi @eldraco, I would love to contribute to this project by adding this new feature, could you kindly explain to me in detail about this so I could start working on it.