[PBNTR-371] [3 of 4] Star Rating kit: add styles and animation

[ElisaShapiro]

What does this PR do? A clear and concise description with your runway ticket url.
PBNTR-371 adds styling from star rating kit handoff to enhance interactive star rating kit (rails version creation ticket, react version creation ticket). This PR adds state managed hover styles, focus styles, adds the dark mode primary star style, and ensures that the PbEnhancedElement code for this kit was added to the new playbook-rails.js created in the recent switch to vite. It reveals the previously created rails and react interactive doc examples, and also adds an interactive star rating kit to the first form doc example.

Screenshots: Screenshots to visualize your addition/change
Rails interactive star rating kit - see selected stars, hover stars, and focus box via keyboard-tabbing


React interactive star rating kit - see selected stars, hover stars, and focus box via keyboard-tabbing


Rails interactive star rating kit on form doc example

Primary star in dark mode (first photo shows current production, where dark mode primary star is still $primary; second photo shows it updated to $active_dark)

How to test? Steps to confirm the desired behavior:

1. Go to star rating kit in review environment (rails, react).
2. (For Rails/React pages): Scroll down to the Interactive doc example and test it by hovering over stars, selecting a set of stars, hovering over additional stars, and making another selection. Test focus by keyboard-tabbing and keyboard-clicking with "enter" or "space" (focus will only work for Interactive doc example).
3. (For Rails/React pages): Switch to dark mode, and retest the interactive doc example there to see dark mode styles. Scroll up to the Color Options doc example to see the new primary dark mode color.
4. (Rails only): Go to the Form kit page, see/interact with the interactive star rating kit at the bottom of the first doc example.

Checklist:

• LABELS Add a label: enhancement, bug, improvement, new kit, deprecated, or breaking. See Changelog & Labels for details.
• DEPLOY I have added the milano label to show I'm ready for a review.
  - [ ] TESTS I have added test coverage to my code.