Update ceno homepage and fix onboarding bugs
This MR addresses issues #90 (closed), #54 (closed), #88 (closed) and relates to #19 (closed). Specific changes include:
- Updated UI for public vs personal browsing card on homepage
- Updated homepage background to march onboarding
- Change 'Private' -> 'Personal' browsing across the app (Note.: Ceno manual currently shows 'private' browsing and will need to be updated)
- Fixes text and button overlap on onboarding screens for lower resolution devices