release: ngx v0.5.0

[bavshin-f5]

0.5.0 final release

[Copilot]

Pull Request Overview

This PR finalizes the release of ngx v0.5.0 by updating version numbers from beta to final release and making related improvements.

• Updates version from "0.5.0-beta" to "0.5.0" in package manifests
• Upgrades allocator-api2 dependency and simplifies related code
• Adds documentation badges and updates changelog for final release

Reviewed Changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/async_/resolver.rs	Uses anonymous lifetime syntax for cleaner code
src/allocator.rs	Imports unsize_box directly and removes custom macro implementation
nginx-sys/Cargo.toml	Updates version from beta to final release
README.md	Adds documentation badges for both ngx and nginx-sys crates
Cargo.toml	Updates version and allocator-api2 dependency version
CHANGELOG.md	Updates changelog with final release notes and migration guidance

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[xeioex]

LGTM.