Reader refinements

[bhajneet]

Motivation

As we work on improving the reading experience for users, there are still a couple pain points which lead to an inefficient flow for long duration readers.

Goal

To improve the reading experience across multiple bookmarks

Stories/Tasks

• Keep screen on option #35
• Add next gesture at bottom and prev at top #27
• Investigate font size change from default to reading mode #285
• pinch to zoom in/out font size ? (do we want this)
• Add scrolling/continuous-scrolling functionality  #40