onboarding ui: Add editing page to onboarding page (#35298)

I added buttons for inlay values, showing the mini map, git blame, and
controlling the UI/Editor Font/Font size. The only thing left for this
page is some UI clean up and adding buttons for setting import from
VSCode/cursor.

I also added Numeric Stepper as a component preview.

Current state:
<img width="1085" height="585" alt="image"
src="https://github.com/user-attachments/assets/230df474-da81-4810-ba64-05673896d119"
/>


Release Notes:

- N/A

Cargo.lock

@@ -10942,9 +10942,12 @@ dependencies = [
  "anyhow",
  "command_palette_hooks",
  "db",
+ "editor",
  "feature_flags",
  "fs",
  "gpui",
+ "language",
+ "project",
  "settings",
  "theme",
  "ui",