Add bionic reading.

[Birdthatcantfly]

I was wondering if it's possible to add bionic reading to the app. This feature might help users to read big articles easily. Bionic reading highlights the first letters in each word, so your eyes focus on those letters, and your brain does the comprehension. https://bionic-reading.com/

There is another bionic reading implementation, which highlights words with color gradients. https://www.beelinereader.com/

[Perdellian]

For a F/OSS example, Librera Reader has this feature. https://github.com/foobnix/LibreraReader