Landing - global leaderboard

User story

As a visitor, I want to see the global leaderboard, so that I can identify the top contributors and their achievements in the "Race of Sloths."

[ ] Include a global leaderboard accessible via a clearly marked tab or section in the main navigation.
[ ] Ensure the link to the leaderboard is one of the focal points of the landing page to attract and retain visitor interest.
[ ] Display key information about each contributor on the leaderboard: Place, GitHub username, Rating, Pull request count and current weekly streak
[ ] Provide tooltips or a small popup on hover/click which gives more detail about the contributor's recent activities or highlights.
[ ] The leaderboard must be updated in real-time or near real-time to reflect the latest scores and rankings.
[ ] Leaderboard should have a switch between global and monthly leaderboards
[ ] The leaderboard should load 20 positions by default with endless scrolling functionality
[ ] Allow users to sort the leaderboard based on different criteria such as highest rating, most recent, or alphabetical order.
[ ] Ensure that the leaderboard loads quickly and efficiently, even with large amounts of data.
[ ] Leaderboard should have two different states:
- [ ] If a user is not logged in, display the normal leaderboard
- [ ] If a user is logged in, display an additional row, showing the user's position and statistics
  - [ ] If the user clicks on his row, the leaderboard should scroll to his position