Add part of the change log for v0.5.0

A source commit: huanshankeji/exposed-gadt-mapping@489fb0b

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Change log
 
+## v0.5.0 / 2024-11-29
+
+Because of [the Exposed SELECT DSL design changes](https://github.com/JetBrains/Exposed/pull/1916), and also because the old `DatabaseClient` creation APIs were poorly designed and too cumbersome, causing an additional cognitive burden on the users, this release has been completely overhauled. Some old APIs are removed directly because deprecating and delegating them to new ones fills the code base with unused code. Therefore, this release is not source-compatible or binary-compatible with v0.4.0. We are sorry for the inconvenience. From this version on, we will try to maintain source and binary compatibility, deprecating APIs instead of removing them in the foreseeable future.
+
+Functional changes:
+
+* ...
+
+Miscellaneous changes:
+
+* add API documentation generated by Dokka hosted at <https://huanshankeji.github.io/exposed-vertx-sql-client/>
+* add CODE_OF_CONDUCT.md and CONTRIBUTING.md
+* use the Kotlin binary compatibility validator
+* bump Exposed to v0.56.0
+
 ## v0.4.0 / 2024-10-19
 
 * bump Exposed to 0.53.0