When you loop over a Typewriter, using a `for-of` statement, you
iterate over all positions in the Typewriters text. These positions
are represented by a `TypewriterPosition`.
`TypewriterPosition` contains the character for that position, the position (index) of that character, and all cursors currently on the position. Lastly it will contain all cursors that have selected the position.
The position of the 'character' in the text.
The Typewriter "normalizes" these so all unicode characters have a length of 1, by calling `Array.from(text)`.