Add a changelog

This is like table stakes for having a usable library.

CHANGELOG.md

@@ -0,0 +1,22 @@
+# Changelog
+
+## 0.3.0.0
+
+* [Bump `aeson` upper bound](https://github.com/joneshf/rollbar-hs/pull/3)
+
+## 0.2.0.0
+
+* [Fix the type of `Notifier` `name`](https://github.com/joneshf/rollbar-hs/commit/11a3a2463cf44735237d062f15a349d8bfa7ffce)
+
+## 0.1.0.1
+
+* [Add synopsis](https://github.com/joneshf/rollbar-hs/commit/272c5764a9657f55e00e31c43a3d583362d823d5)
+
+## 0.1.0.0
+
+* Extract core rollbar to its own package
+
+    This is almost entirely copy-pasted from [`wai-middleware-rollbar` version 0.8.4](https://hackage.haskell.org/package/wai-middleware-rollbar-0.8.4).
+
+    The intent is to make the core data types available for other packages.
+    If this gets unweildy, move it right back.

package.yaml

@@ -5,6 +5,7 @@ description: |
   Provides a type-safe encoding of the Rollbar API.
   Also provides functions to communicate with the Rollbar API.
 extra-source-files:
+  - CHANGELOG.md
   - README.md
 github: joneshf/rollbar-hs
 library: