Generate changelog and add PR template (#27)

* Generate CHANGELOG.md file using notes from previous GH releases

* Add pull request template

* Update CI in PS to v0.14.0-rc5

Author: JordanMartinez

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,12 @@
+**Description of the change**
+
+Clearly and concisely describe the purpose of the pull request. If this PR relates to an existing issue or change proposal, please link to it. Include any other background context that would help reviewers understand the motivation for this PR.
+
+---
+
+**Checklist:**
+
+- [ ] Added the change to the changelog's "Unreleased" section with a reference to this PR (e.g. "- Made a change (#0000)")
+- [ ] Linked any existing issues or proposals that this pull request should close
+- [ ] Updated or added relevant documentation
+- [ ] Added a test for the contribution (if applicable)

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
 
       - uses: purescript-contrib/setup-purescript@main
         with:
-          purescript: "0.14.0-rc3"
+          purescript: "0.14.0-rc5"
 
       - uses: actions/setup-node@v1
         with:

CHANGELOG.md

@@ -0,0 +1,47 @@
+# Changelog
+
+Notable changes to this project are 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).
+
+## [Unreleased]
+
+Breaking changes:
+
+New features:
+
+Bugfixes:
+
+Other improvements:
+
+## [v2.1.1](https://github.com/purescript/purescript-math/releases/tag/v2.1.1) - 2018-05-22
+
+Relicensed as BSD3
+
+## [v2.1.0](https://github.com/purescript/purescript-math/releases/tag/v2.1.0) - 2017-06-25
+
+Add `τ` constant (@FranklinChen)
+
+## [v2.0.0](https://github.com/purescript/purescript-math/releases/tag/v2.0.0) - 2016-06-04
+
+This release is intended for the PureScript 0.9.1 compiler and newer.
+
+## [v2.0.0-rc.1](https://github.com/purescript/purescript-math/releases/tag/v2.0.0-rc.1) - 2016-05-20
+
+- Remainder operator is now an alias for a function
+
+## [v1.0.0](https://github.com/purescript/purescript-math/releases/tag/v1.0.0) - 2016-04-13
+
+- Added `trunc` (@rgrempel)
+- Moved out of RC status. No breaking code changes have been made since `v0.2.0`.
+
+## [v0.2.0](https://github.com/purescript/purescript-math/releases/tag/v0.2.0) - 2015-06-30
+
+This release works with versions 0.7.\* of the PureScript compiler. It will not work with older versions. If you are using an older version, you should require an older, compatible version of this library.
+
+## [v0.1.1](https://github.com/purescript/purescript-math/releases/tag/v0.1.1) - 2015-03-22
+
+Updated docs
+
+## [v0.1.0](https://github.com/purescript/purescript-math/releases/tag/v0.1.0) - 2014-04-25
+
+
+