chore: Prepare v0.19.0 (#119)

Signed-off-by: Max Inden <mail@max-inden.de>

Author: mxinden

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.19.0-alpha.2]
+## [0.19.0]
 
 This is a large release including multiple breaking changes. Major user-facing
 improvement of this release is support for the OpenMetrics Protobuf format.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "prometheus-client"
-version = "0.19.0-alpha.2"
+version = "0.19.0"
 authors = ["Max Inden <mail@max-inden.de>"]
 edition = "2021"
 description = "Open Metrics client library allowing users to natively instrument applications."