Changes on text reader UI

[tentamdin]

Description
Changes requirements to app from meeting on 4 March. For better UX.

Subtasks

• On reader, update the serif to san fonts to some of system label
• Text segments from start rather than middle
• Fix language and version change feature on reader
  In commentary section,
  • need three dots at end of para.
  • title is grey in the above sefaria app. so we need the same for our webuddhist.
• remove red background highlight for few seconds instead grey out other sgments
• just show the audio play button as we will have in future.