- Fixed a breaking issue where "j" and "k" keys could no longer typed

- Fixed issue with extension not loading sometimes on Firefox

Feature:
- Changed keybinds to match Vim bindings - k is up and j is down now

Bug Fixes:
- Refactored code, simplifying it and splitting it into multiple files
- FIxed element being hidden by the Google top bar
- Fixed elements not being focused sometimes on load
- Fixed initially highlighted element not being focused
- Fixed not all top-level links being detected