Add a message on how to release to contributing guide

CHANGELOG.md

@@ -6,6 +6,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+## [2.0.6] - 2019-10-03
+### Added
 - Support for Rails 6 [#228](https://github.com/rswag/rswag/pull/228)
 - Support for Windows paths [#176](https://github.com/rswag/rswag/pull/176)
 ### Changed
@@ -15,4 +23,4 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 ### Security
 
-## [2.0.5] - 2018-07-10
+## [2.0.5] - 2018-07-10

CONTRIBUTING.md

@@ -43,3 +43,17 @@ bundle exec rspec
 Push to your fork and [submit a Pull Request][pr].
 
 [pr]: https://github.com/rswag/rswag/compare/
+
+## Release
+(for maintainers)
+
+Update the changelog.md, putting the new version number in and moving the Unreleased marker.
+
+Merge the changes into master you wish to release.
+
+Add and push a new git tag, annotated tags preferred:
+```
+git tag -s 2.0.6 -m 'v2.0.6'
+```
+
+Travis will detect the tag and release all gems with that tag version number.