Update changelog for 0.3.0 release

Author: b-cho

CHANGELOG.md

@@ -4,16 +4,9 @@ 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).
 
-## Releases
-
-- [[0.3.0]](#030) (unreleased)
-- [[0.2.0]](#020) (2021-01-30)
-- [[0.1.1]](#011) (2021-01-23)
-- [[0.1.0]](#010) (2021-01-23)
-
 ---
 
-### [0.3.0]
+### [0.3.0] (2021-05-03)
 
 #### Added
 
@@ -54,7 +47,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
   > const galeforce = new GaleforceModule(); // now OK, but requests requiring an API key will return a 401 Unauthorized error.
   > ```
 
-### [0.2.0]
+### [0.2.0] (2021-01-30)
 
 #### Added
 
@@ -67,13 +60,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - **[breaking]** Split ~~`galeforce.lol.mastery.summoner`~~ into **`galeforce.lol.mastery.champion`** and **`galeforce.lol.mastery.list`**.
 - **[breaking]** Change CommonJS / `require()` import method to no longer allow `.default`.
 
-### [0.1.1]
+### [0.1.1] (2021-01-23)
 
 #### Changed
 
 - Fix a major bug preventing the library from initializing properly on Node.js ≤ 13.
 
-### [0.1.0]
+### [0.1.0] (2021-01-23)
 
 #### Added