Add v3.0.0 changelog

Author: arafattehsin

CHANGELOG.md

@@ -5,25 +5,102 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.0.0] - 2026-01-27
+
+### 🎉 Major Release: Multi-Engine Architecture
+
+This release transforms SentimentAnalyzer from a single ML.NET-based package into a modular, multi-engine sentiment analysis suite with 4 distinct NuGet packages.
+
+### New Packages
+
+#### SentimentAnalyzer.Core 3.0.0
+
+- **New Package**: Lightweight VADER-based sentiment analysis (<1 MB)
+- Uses VaderSharp2 for rule-based sentiment scoring
+- ~75% accuracy on general sentiment tasks
+- No ML model files required
+- Perfect for size-constrained applications
+
+#### SentimentAnalyzer.Onnx 3.0.0
+
+- **New Package**: High-accuracy TinyBERT transformer model (~18 MB)
+- 94.2% accuracy on sentiment classification
+- Embedded ONNX model (no external downloads)
+- Supports .NET Standard 2.0, .NET 8, and .NET 10
+- Cross-platform (Windows, Linux, macOS, iOS, Android)
+
+#### SentimentAnalyzer.Onnx.Multilingual 3.0.0
+
+- **New Package**: Multilingual DistilBERT model supporting 104 languages
+- ~88% accuracy across multiple languages
+- Downloads 270 MB model on first use (cached locally)
+- Async download support with progress reporting
+- Fixed HuggingFace ONNX export bug (correctly exported model hosted on GitHub Releases)
+
+### SentimentAnalyzer 3.0.0 (Legacy)
+
+- Maintained for backward compatibility
+- Upgraded ML.NET from 1.5.5 to 5.0.0
+- No API changes - drop-in replacement for v2.x
+- Multi-targeting: .NET Standard 2.0, .NET 8, .NET 10
+
+### New Features
+
+- **Fluent Builder API**: `SentimentAnalyzer.CreateBuilder().UseVader().Build()`
+- **ISentimentEngine Interface**: Create custom sentiment engines
+- **Thread-Safe**: All engines are thread-safe and can be reused
+- **Comprehensive Test Suite**: 58 tests across Core.Tests and integration tests
+- **Sample Applications**: Console, Blazor WASM, MAUI, BenchmarkDotNet samples
+
+### Architecture Changes
+
+- Modular design allowing mix-and-match of engines
+- Shared core abstractions (`ISentimentEngine`, `SentimentResult`, `SentimentLabel`)
+- Package size optimization (choose what you need)
+
+### Documentation
+
+- Comprehensive README with engine comparison table
+- Performance benchmarks and accuracy metrics
+- Migration guide for v2.x users
+- API reference for all packages
+
+### Breaking Changes from 2.x
+
+- New namespace structure (see migration guide)
+- Builder pattern required for new engines
+- Legacy `Sentiments.Predict()` API moved to SentimentAnalyzer package
+
+### Model Hosting
+
+- TinyBERT model: Embedded in SentimentAnalyzer.Onnx package
+- DistilBERT model: Hosted on GitHub Releases (correctly exported ONNX model)
+- Vocab files: Downloaded from HuggingFace
+
 ## [2.0.0] - 2026-01-22
 
 ### Added
+
 - Multi-targeting support for `.NET Standard 2.0`, `.NET 8`, and `.NET 10`
 - Package README included in NuGet package
 - Additional package tags for better discoverability
 
 ### Changed
+
 - **Upgraded ML.NET from 1.5.5 to 5.0.0** - This is a major dependency upgrade
 - Updated package description and metadata
 - Test project upgraded to .NET 8 with latest test framework versions
 
 ### Compatibility
+
 This release maintains **full backward compatibility** with v1.x:
+
 - The API (`Sentiments.Predict(text)`) remains unchanged
 - The `SentimentPrediction` model is unchanged
 - Existing code will work without modifications
 
 ### Migration Guide
+
 No code changes required. Simply update your package reference:
 
 ```xml
@@ -35,28 +112,31 @@ No code changes required. Simply update your package reference:
 ```
 
 ### Platform Support
-| Platform | Supported |
-|----------|-----------|
+
+| Platform              | Supported               |
+| --------------------- | ----------------------- |
 | .NET Framework 4.6.1+ | ✅ (via netstandard2.0) |
-| .NET Core 2.0+ | ✅ (via netstandard2.0) |
-| .NET 5/6/7 | ✅ (via netstandard2.0) |
-| .NET 8 (LTS) | ✅ Native |
-| .NET 10 (LTS) | ✅ Native |
-| .NET MAUI | ✅ |
-| Blazor (Server/WASM) | ✅ |
-| Unity | ✅ (via netstandard2.0) |
+| .NET Core 2.0+        | ✅ (via netstandard2.0) |
+| .NET 5/6/7            | ✅ (via netstandard2.0) |
+| .NET 8 (LTS)          | ✅ Native               |
+| .NET 10 (LTS)         | ✅ Native               |
+| .NET MAUI             | ✅                      |
+| Blazor (Server/WASM)  | ✅                      |
+| Unity                 | ✅ (via netstandard2.0) |
 
 ---
 
 ## [1.2.3] - 2021-xx-xx
 
 ### Changed
+
 - Performance improvements using singleton pattern
 - Based on ML.NET version 1.5.5
 
 ## [1.0.0] - 2020-xx-xx
 
 ### Added
+
 - Initial release
 - Binary sentiment analysis (positive/negative)
 - Offline, on-device prediction