Fix changelog and docs

CHANGELOG.md

@@ -5,6 +5,8 @@ All notable changes to this project will be 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
+
 ## 1.10.2
 ## What's Changed
 * Update CHANGELOG.md by @juanjjaramillo in https://github.com/newrelic/k8s-metadata-injection/pull/302

CONTRIBUTING.md

@@ -16,7 +16,22 @@ Before submitting an Issue, please search for similar ones in the
 
 1. Ensure any install or build dependencies are removed before the end of the layer when doing a build.
 2. Increase the version numbers in any examples files and the README.md to the new version that this Pull Request would represent. The versioning scheme we use is [SemVer](http://semver.org/).
-3. You may merge the Pull Request in once you have the sign-off of two other developers, or if you do not have permission to do that, you may request the second reviewer to merge it for you.
+3. Add an entry as an unordered list to the CHANGELOG under the `Unreleased` section under an L3 header that specifies the type of your PR. If there is no L3 header for your type of PR already in the Unreleased section, add a new L3 header. Here's an example of how it should look:
+    ```md
+      ## Unreleased
+
+      ### bugfix
+      - Fix some bug in some file
+    ```
+
+  - Here are the accepted L3 headers (case sensitive)
+    + `breaking`
+    + `security`
+    + `enhancement`
+    + `bugfix`
+    + `dependency`
+
+4. You may merge the Pull Request in once you have the sign-off of one other developers, or if you do not have permission to do that, you may request the other reviewer to merge it for you.
 
 ## Contributor License Agreement