Show correct number of characters typed in WPM calculations

[NicksPatties]

When calculating wpm, I incorrectly say the number of characters typed is the length of the number of events without backspaces that were made. This means that characters that were corrected are counted twice in the number of characters, which makes the wpm faster than it's supposed to be.

I also cannot calculate the number of typed characters by the index of the event. This is because the character typed index does not properly account for \n\tcases, like this:

Todo:
  - Eat pudding

• The index of the newline on line 1 is 5
• The index of - after the tab on line 2 is 7

This means that the number of characters would be greater than what the user actually typed.

Fix the char count to correctly calculate wpm.