chore: added contribution guide

CONTRIBUTING.md

@@ -0,0 +1,23 @@
+# Contribution guide
+
+## Ground Rules
+
+A few general guidelines:
+
+- For major changes, please open an issue first to discuss what you would like to change.
+- Contributors should fork the repository and work on fixes or enhancements on their own fork.
+  - Use the [pull request feature](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request-from-a-fork) to submit your changes to this repository.
+  - Committing directly to main is not possible.
+  - All pull requests should be rebased (with main) and commits squashed prior to the final merge process.
+  - Use [conventional commit](https://www.conventionalcommits.org/en/v1.0.0/) formatting for commit messages.
+  - Do not combine fixes for multiple issues into one branch. Use a separate branch for each issue you’re working on.
+- Please include unit tests with all your code changes.
+  - All unit tests must be 100% passing before the pull requests will be approved and merged.
+
+## Report a bug
+
+Please open an issue where you describe the bug and steps to reproduce. However, do NOT create an issue for security vulnerabilities, see [SECURITY.md](https://github.com/equinor/pepm-ui/blob/main/SECURITY.md) for security reporting.
+
+## How to suggest a feature or enhancement
+
+Please open an issue where you describe the feature or enhancement you would like to add or change.