Replace single changelog with one for each gem.

CONTRIBUTING.md

@@ -127,19 +127,17 @@ New files in your code contributions should contain the following license header
 
 ## Changelog
 
-OpenSearch-ruby maintains a version specific changelog by enforcing a change to the ongoing [CHANGELOG](CHANGELOG.md) file adhering to the [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) format.
+OpenSearch-ruby maintains a version specific changelog for each gem adhering to the [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) format.
 
 The changes are curated by version, with the changes to the main branch added chronologically to the `Unreleased` version. Each version has corresponding sections which list out the category of the change - `Added`, `Changed`, `Deprecated`, `Removed`, `Fixed`, `Security`.
 
 
 ### Adding Changes
 
-As a contributor, you must ensure that every pull request has its changes listed out within the corresponding version and appropriate section of the [CHANGELOG](CHANGELOG.md) file.
+As a contributor, you must ensure that every pull request has its changes listed out within the corresponding gem, version, and appropriate section of the file.
 
-Adding in the change is a two step process -
-1. Add your changes to the corresponding section within the CHANGELOG file with dummy pull request information, publish the PR.
+Each change must reference the Pull Request or the Issue it addresses.
 
-2. Update the entry for your change in [`CHANGELOG.md`](CHANGELOG.md) and make sure that you reference the pull request there.
 
 ## Review Process
 

opensearch-api/CHANGELOG.md

@@ -0,0 +1,18 @@
+# CHANGELOG
+Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+
+## [Unreleased]
+### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+## 2.1.0
+### Changed
+- Update comments around deprecated and inclusive naming ([#112](https://github.com/opensearch-project/opensearch-ruby/pull/112))
+### Removed
+- Remove deprecated escape_utils ([#74](https://github.com/opensearch-project/opensearch-ruby/pull/74))
+### Fixed
+- Fixing tests related to escape utils latest version ([#73](https://github.com/opensearch-project/opensearch-ruby/pull/73))

opensearch-aws-sigv4/CHANGELOG.md

@@ -0,0 +1,14 @@
+# CHANGELOG
+Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+
+## [Unreleased]
+### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+## 1.0.0
+### Added
+- Added `OpenSearch::AWS::Sigv4Client` ([#110](https://github.com/opensearch-project/opensearch-ruby/pull/110))

opensearch-dsl/CHANGELOG.md

@@ -0,0 +1,14 @@
+# CHANGELOG
+Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+
+## [Unreleased]
+### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+## 0.2.1
+### Fixed
+- Fixed Mocha Dependency ([#108](https://github.com/opensearch-project/opensearch-ruby/pull/108))

opensearch-ruby/CHANGELOG.md

@@ -0,0 +1,15 @@
+# CHANGELOG
+Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+
+## [Unreleased]
+### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+## 2.1.0
+### Changed
+- Use safe_load instead of load for yaml ([#77](https://github.com/opensearch-project/opensearch-ruby/pull/77))
+- Update comments around deprecated and inclusive naming ([#112](https://github.com/opensearch-project/opensearch-ruby/pull/112))

opensearch-transport/CHANGELOG.md

@@ -0,0 +1,15 @@
+# CHANGELOG
+Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+
+## [Unreleased]
+### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+## 2.1.0
+### Changed
+- Faraday 2 support for opensearch-transport ([#76](https://github.com/opensearch-project/opensearch-ruby/pull/76))
+- Ruby 2.6 works with faraday-typhoeus ([#88](https://github.com/opensearch-project/opensearch-ruby/pull/88))