Introduced the `loadingBuilder` parameter to allow for manual loading UI while bypassing automatic skeleton generation. Refined default visual constants for a more subtle shimmer effect and improved color configuration handling.

- Added `loadingBuilder` to `AutoShimmerAnimate` to support custom loading widgets that still benefit from the shimmer animation.
- Updated default highlight color to a soft light grey (`0xFFFAFAFA`) and reduced default highlight width to `0.08`.
- Modified `ShimmerWrapper` to ensure `highlightColor` and `highlightOpacity` are applied even when animation overrides are not present.
- Enhanced `AutoShimmerAnimate` logic to prioritize `loadingBuilder` over auto-generated skeletons.
- Expanded `README.md` with detailed usage examples for layered skeletons, custom loading UI, and parameter tables.
- Added comprehensive unit tests for `loadingBuilder` logic, shimmer builder wrapping, and color override persistence.
- Updated `CHANGELOG.md` to reflect version 0.1.1 changes.