{doc} Update README & CHANGELOG for 3.0

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 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).
 
-## 3.0.0 (in progress)
+## [3.0.0](https://github.com/asmaloney/libE57Format/releases/tag/v3.0.0) - 2023-02-23
 
 There have been _many_ changes around the `Simple API` in this release to fix some problems, avoid potential errors, and simplify the use of the API. Where possible these changes are marked as `deprecated` to be removed later. The compiler will produce warnings for these indicating what needs to change. Other changes could not be marked deprecated but will break the API, requiring code changes. The notable ones are marked with 🚧 below.
 

README.md

@@ -4,14 +4,6 @@
 
 libE57Format is a library which provides read & write support for the E57 file format.
 
-## 🚨 Version 3.0 Note 🚨
-
-There have been many changes (especially to the "Simple API") in the upcoming version 3.0 - some of which will require code changes on your end. Please see the [CHANGELOG](CHANGELOG.md) for details.
-
-Since this version is breaking the API, I am happy to discuss any other API-breaking changes which might be useful. Please raise them in [this issue](https://github.com/asmaloney/libE57Format/issues/177).
-
-I plan to let 3.0 sit in the master branch until the end of 2022. If I don't hear any feedback I will go ahead and release it as-is.
-
 ## Documentation
 
 The doxygen-generated documentation may be [found here](https://asmaloney.github.io/libE57Format-docs/). These docs are generated and saved in the [libE57Format-docs](https://github.com/asmaloney/libE57Format-docs) repo.