VSpot v4.0.0: Multi-step tours, Style API, and build system updates

*   **VSpotView Refactor**: Completely refactored `VSpotView` and `VSpotMessageView` to support multi-step product tours, a new `Step` API, and a comprehensive `Style` system for UI customization.
*   **Performance Improvements**: Optimized drawing logic to eliminate bitmap allocations within `onDraw()` and improved layout positioning.
*   **New Features**: Added support for circular and rounded rectangle spotlight shapes, connector lines, pulse effects, and built-in navigation controls (Back, Next, Skip, Done).
*   **Build System**: Updated Gradle to 9.4.1, Android SDK to 37, and added specialized scripts for Maven Central and JitPack publishing.
*   **Documentation**: Overhauled `README.md` with detailed usage guides, migration instructions, and API documentation for version 4.0.0.
*   **Cleanup**: Removed legacy `MainActivity2` and temporary view implementations (`VSpotView2`, `VSpotMessageView2`).

Updated Gradle

Updated Gradle

Updated gradle

Updated gradle

Updated minSdkVersion

Updated Gradle

Gradle changes

Version change

Support For Older Versions Android Upto API 15