Added documentation for changelogs

Author: MaciejKaras

.github/pull_request_template.md

@@ -7,17 +7,24 @@
 <!-- Enter your proof that it works here.-->
 
 ## Checklist
+
 - [ ] Have you linked a jira ticket and/or is the ticket in the title?
 - [ ] Have you checked whether your jira ticket required DOCSP changes?
-- [ ] Have you checked for release_note changes?
+- [ ] Have you added changelog file?
+    - use `skip-changelog` label if not needed
+    - refer
+      to [Changelog files and Release Notes](https://github.com/mongodb/mongodb-kubernetes/blob/master/CONTRIBUTING.md#changelog-files-and-release-notes)
+      section in CONTRIBUTING.md for more details
 
 ## Reminder (Please remove this when merging)
+
 - Please try to Approve or Reject Changes the PR, keep PRs in review as short as possible
-- Our Short Guide for PRs: [Link](https://docs.google.com/document/d/1T93KUtdvONq43vfTfUt8l92uo4e4SEEvFbIEKOxGr44/edit?tab=t.0)
+- Our Short Guide for
+  PRs: [Link](https://docs.google.com/document/d/1T93KUtdvONq43vfTfUt8l92uo4e4SEEvFbIEKOxGr44/edit?tab=t.0)
 - Remember the following Communication Standards - use comment prefixes for clarity:
-  * **blocking**: Must be addressed before approval.
-  * **follow-up**: Can be addressed in a later PR or ticket.
-  * **q**: Clarifying question.
-  * **nit**: Non-blocking suggestions.
-  * **note**: Side-note, non-actionable. Example: Praise 
-  * --> no prefix is considered a question
+    * **blocking**: Must be addressed before approval.
+    * **follow-up**: Can be addressed in a later PR or ticket.
+    * **q**: Clarifying question.
+    * **nit**: Non-blocking suggestions.
+    * **note**: Side-note, non-actionable. Example: Praise
+    * --> no prefix is considered a question

CONTRIBUTING.md

@@ -1,7 +1,51 @@
 # Summary
+
 Contributing to the Mongodb Controllers for Kubernetes (MCK) project
-Pull requests are always welcome, and the MCK dev team appreciates any help the community can give to help make MongoDB better.
+Pull requests are always welcome, and the MCK dev team appreciates any help the community can give to help make MongoDB
+better.
+
+## PR Prerequisites
 
-# PR Prerequisites
-* Please ensure you have signed our Contributor Agreement. You can find it [here](https://www.mongodb.com/legal/contributor-agreement).
+* Please ensure you have signed our Contributor Agreement. You can find
+  it [here](https://www.mongodb.com/legal/contributor-agreement).
 * Please ensure that all commits are signed.
+* Create a changelog file that will describe the changes you made. Use the `skip-changelog` label if your changes do not
+  require a changelog entry.
+
+## Changelog files and Release Notes
+
+Each Pull Request usually has a changelog file that describes the changes made in the PR using Markdown syntax.
+Changelog files are placed in the `changelog/` directory and used to generate the Release Notes for the
+upcoming release. Preview of the Release Notes is automatically added as comment to each Pull Request.
+The changelog file needs to follow the naming convention
+`YYYYMMDD-<change_kind>-<short-description>.md`. To create changelog file please use the
+`scripts/release/create_changelog.py` script. Example usage:
+
+```console
+python3 -m scripts.release.create_changelog --kind fix "Fix that I want to describe in the changelog"
+```
+
+For more options, run the script with `--help`:
+
+```console
+python3 -m scripts.release.create_changelog --help
+usage: create_changelog.py [-h] [-c ] [-d ] [-e] -k  title
+
+Utility to easily create a new changelog entry file.
+
+positional arguments:
+  title                 Title for the changelog entry
+
+options:
+  -h, --help            show this help message and exit
+  -c, --changelog-path
+                        Path to the changelog directory relative to the repository root. Default is changelog/
+  -d, --date            Date in 'YYYY-MM-DD' format to use for the changelog entry. Default is today's date
+  -e, --editor          Open the created changelog entry in the default editor (if set, otherwise uses 'vi'). Default is True
+  -k, --kind            Kind of the changelog entry:
+                          - 'prelude' for prelude entries
+                          - 'breaking, major' for breaking change entries
+                          - 'feat, feature' for feature entries
+                          - 'fix, bugfix, hotfix, patch' for bugfix entries
+                          - everything else will be treated as other entries
+```