add current changelog for 1.1 (#83)

Signed-off-by: Josh Gwosdz <jgwosdz@redhat.com>

CHANGELOG.md

@@ -0,0 +1,42 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is loosely based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+Helper to list all merge commits between a release and HEAD: `git log --oneline --reverse 1.0...HEAD`
+
+## Diffs
+[Unreleased]: https://github.com/prometheus-community/jiralert/compare/1.0...HEAD
+[1.0]: https://github.com/prometheus-community/jiralert/compare/0.6...1.0
+[0.6]: https://github.com/prometheus-community/jiralert/compare/0.5...0.6
+[0.5]: https://github.com/prometheus-community/jiralert/compare/0.4...0.5
+[0.4]: https://github.com/prometheus-community/jiralert/compare/0.3...0.4
+[0.3]: https://github.com/prometheus-community/jiralert/compare/0.2...0.3
+[0.2]: https://github.com/prometheus-community/jiralert/compare/0.1...0.2
+[0.1]: https://github.com/prometheus-community/jiralert/releases/tag/0.1
+
+## [1.1] - Unreleased
+### Added
+- Jiralert docker image [#22](https://github.com/prometheus-community/jiralert/pull/22)
+- Slack button in Readme [#23](https://github.com/prometheus-community/jiralert/pull/23)
+  - Migrate to github actions [#81](https://github.com/prometheus-community/jiralert/pull/81)
+  - Add CircleCI [#33](https://github.com/prometheus-community/jiralert/pull/33
+  - Update circleci/golang version from 1.12 to 1.14 [#76](https://github.com/prometheus-community/jiralert/pull/76)
+- Adds match and stringSlice to template functions [#55](https://github.com/prometheus-community/jiralert/pull/55)
+- Add ReopenDuration handling: otherwise Jira issue is never reopened [#61](https://github.com/prometheus-community/jiralert/pull/61)
+
+### Changed
+- Migrate from dep to go modules [#24](https://github.com/prometheus-community/jiralert/pull/24)
+- Split project into separate go packages [#27](https://github.com/prometheus-community/jiralert/pull/27)
+- Switch logging from glog to go-kit/log [#31](https://github.com/prometheus-community/jiralert/pull/31)
+- Use Docker multistage builds [#44](https://github.com/prometheus-community/jiralert/pull/44)
+- Synchronize Makefile.common from prometheus/prometheus [#60](https://github.com/prometheus-community/jiralert/pull/60)
+- Synchronize common files from prometheus/prometheus [#63](https://github.com/prometheus-community/jiralert/pull/63)
+- Update common Prometheus files [#71](https://github.com/prometheus-community/jiralert/pull/71)
+
+### Fixed
+- Fix sample configuration file linting issues [#68](https://github.com/prometheus-community/jiralert/pull/68)
+- Update the description field on open issues [#75](https://github.com/prometheus-community/jiralert/pull/75)
+- error if http method for home or config is not GET [#78](https://github.com/prometheus-community/jiralert/pull/78)
+
+### Removed
+- Remove -ignore flag from Makefile, fix log.level info [#42](https://github.com/prometheus-community/jiralert/pull/42)