添加 GitHub Pages 文档与 CI 修复

新增功能：
- docs/ 目录：GitHub Pages 静态页面
  - index.html：项目主页
  - og-image.png/svg：社交分享图片
- tests/rustls_provider.rs：rustls CryptoProvider 集成测试
- rustls_provider 模块增强：
  - hash.rs：新增测试和文档
  - hmac.rs：新增测试和文档
  - kx.rs：新增测试和文档
  - sign.rs：新增测试和文档
  - verify.rs：新增测试和文档

CI 修复：
- rustls 依赖改为 git 源，避免本地路径依赖问题
- 简化 SM3 HMAC 流式测试，移除 alloc 依赖
- 移除未使用的 extern crate alloc
- 代码格式化

文档更新：
- README.md：添加 GitHub Pages 链接
- CHANGELOG.md：更新变更记录
- Cargo.toml：添加 dev-dependencies

CHANGELOG.md

@@ -52,6 +52,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **SM4 AEAD combined format**
   - `sm4_encrypt_gcm_combined` / `sm4_decrypt_gcm_combined`: TLS format (ciphertext||tag)
   - `sm4_encrypt_ccm_combined` / `sm4_decrypt_ccm_combined`: Same format for CCM
+
+## [0.2.0] - 2025-03-08
+
+### Added
+
 - **BLS signatures** (`bls` module, requires `alloc` feature)
   - `bls_keygen` / `bls_sign` / `bls_verify`: minimal-signature-size variant (sig ∈ G1, pk ∈ G2)
   - `bls_aggregate` / `bls_aggregate_verify`: multi-message aggregate signatures
@@ -92,9 +97,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - MSRV raised to 1.83.0 (required by crypto-bigint 0.6.x for ConstMontyForm constant-time Montgomery arithmetic)
 - Use Rust 1.83+ built-in `div_ceil` method instead of manual implementation
-
-### CI
-
 - Optimized sanity_check.sh to skip test code, avoiding false positives
 
 ## [0.1.0] - 2025-03-07