FEI-5465.5: Lesson 4 - Splitting up large components

[kevinbarabash]

Summary:

Lesson 4 covers how splitting up large components into smaller components can help avoid unnecessary renders.

Issue: FEI-5465

Test plan:

• yarn dev
• http://localhost:5173/react-render-perf/lesson-04/exercise
• profile, click the "click me!" buttons, see that LargeComponent takes +800ms to re-render
• http://localhost:5173/react-render-perf/lesson-04/solution
• profile, click the "click me!" buttons, see that only of the three shape components re-render and only takes about +250ms

[jaredly]

looks good!