Update changelog guidelines (#8395)

docs/project/contributing.md

@@ -130,3 +130,20 @@ Any user-facing change should be labeled with `include-changelog`.
 The PR title should contain a concise summary of the feature or fix and the description should have the GitHub issue number.
 When we publish a new version of lakeFS, we will add this to the relevant version section of the changelog.
 If the change should not be included in the changelog, label it with `exclude-changelog`.
+
+### User-Facing Changes Examples
+1. UI/UX modifications: Changes to the layout, color scheme, or navigation structure.
+1. New features: Adding functionality that users can directly interact with, unless defined as internal.
+1. Configuration changes: Updates to settings that users can adjust.
+1. Performance improvements: Enhancements that noticeably speed up the application.
+1. Bug fixes.
+1. Security updates: Changes that address vulnerabilities or privacy concerns.
+
+### Non-User-Facing Changes:
+1. Code refactoring: Restructuring the codebase without changing its external behavior.
+1. Backend optimizations: Improvements to server-side processes that don't noticeably affect performance.
+1. Database schema changes: Modifications to the data structure that don't alter the user interface **and** do not require data migration.
+1. Development tooling updates: Changes to build processes or development environments.
+1. Internal API: Adding/Altering APIs tagged as internal.
+1. Documentation updates.
+1. Imported libraries: Updates to third-party libraries that don't introduce security updates.