Feature Request: Display key accuracy on "Key Typing Speed" chart

[saltedlolly]

It would be extremely helpful if the "Key Typing Speed" chart for each key also included the accuracy of that key. i.e. How often, when we are meant to hit this particular key, are we hitting it, rather than accidentally hitting some other key? This would make it easy to identify the keys we need to spend more time practising.

This could also help identify the words or patterns we struggle most with and create practice sessions to target them specifically.

Previously shared this request here: https://discord.com/channels/930786115810643978/1302968636658417755