Save Visual Adjustments between sessions

**Context**

> Is your feature request related to a problem? What is the motivation for implementing this feature?

Its an enhancement/annoyance. I love the reader I use it a lot. I tend to invert the colors and adjust the contrast. I also borrow a lot of books for just an hour at a time. Anyway when I borrow it remembers my bookmarks, but I have to redo the adjustments everytime. It would be really cool if it remembered by adjustments on a book and opened back up the same way. I also use single page view, but that's not as annoying at the color adjustments. Thanks again for making this super awesome reader.

**Proposal & Constraints**

> What is the proposed solution / implementation? Is there a precedent for this approach succeeding elsewhere?

> Which suggestions or requirements should be considered for how this feature needs to appear or be implemented?

**Additional Resources**

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**Success Metrics**

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**Stakeholders**

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