Developer center UI updates and improvements

We recently held a one-day hackathon focused on quick improvements based on known issues and feedback from our community. Check out what's new below!

1. Personalized welcome headers with your profile name 👋
2. Search by app name to make locating your app a breeze (and it even auto-focuses on the search bar when you open the app page!) 🔍
3. Open links in new tabs or windows (with a right-click) 🪟

4. Create a new app version or promote a draft from any page 💥
5. Search by feature name instead of scrolling through a long list (and it even auto-focuses on the search bar when you open the feature page!) 🔍
6. More descriptive app feature names for new app features (e.g., Board View feature or Account Settings View feature) ✍️

7. The left-pane menu won't jump when you switch between tabs ⚓
8. Smaller header on the App versions tab so you have more real estate to manage versioning 📂