ST-3638: Adding contributing guide line from cp-docker-images repo

CONTRIBUTING.md

@@ -0,0 +1,125 @@
+# Contributing
+
+## General Guidelines
+
+When submitting a pull request (PR), please use the following
+guidelines:
+
+-   Make sure your code respects existing formatting conventions. In
+    general, follow the same coding style as the code that you are
+    modifying.
+-   Do add/update documentation appropriately for the change you are
+    making.
+-   If you are introducing a new feature you may want to first submit
+    your idea for feedback to the [Confluent mailing
+    list](mailto:[email protected]).
+-   Non-trivial features should include unit tests covering the new
+    functionality.
+-   Bugfixes should include a unit test or integration test reproducing
+    the issue.
+-   Try to keep pull requests short and submit separate ones for
+    unrelated features, but feel free to combine simple bugfixes/tests
+    into one pull request.
+-   Keep the number of commits small and combine commits for related
+    changes.
+-   Each commit should compile on its own and ideally pass tests.
+-   Keep formatting changes in separate commits to make code reviews
+    easier and distinguish them from actual code changes.
+
+## GitHub Workflow
+
+1.  Fork the confluentinc/cp-docker-images repository into your GitHub
+    account
+
+    > <https://github.com/confluentinc/cp-docker-images/fork>
+
+2.  Clone your fork of the GitHub repository
+
+    ```
+    $ git clone <[email protected]>:\<username\>/cp-docker-images.git
+    ```
+
+    > Note: replace \<username\> with your GitHub username.
+
+3.  Add a remote to keep up with upstream changes
+    
+    ```
+    $ git remote add upstream https://github.com/confluentinc/cp-docker-images.git
+    ```
+
+    > If you already have a copy, fetch upstream changes
+
+    ```
+    git fetch upstream
+    ```
+
+4.  Create a feature branch to work in
+
+    ```
+    $ git checkout -b feature-xxx remotes/upstream/master
+    ```
+
+5.  Work in your feature branch
+
+    ```
+    $ git commit -a
+    ```
+
+6.  Periodically rebase your changes
+
+    ```
+    $ git pull \--rebase
+    ```
+
+7.  When done, combine (\"squash\") related commits into a single one
+
+    ```
+    $ git rebase -i upstream/master
+    ```
+    >
+    > This will open your editor and allow you to re-order commits and merge
+    > them: - Re-order the lines to change commit order (to the extent
+    > possible without creating conflicts) - Prefix commits using s (squash)
+    > or f (fixup) to merge extraneous commits.
+
+8.  Submit a pull-request
+
+    ```
+    $ git push origin feature-xxx
+    ```
+    >
+    > Go to your cp-docker-images fork main page
+    
+    ``` 
+    <https://github.com/>\<username\>/cp-docker-images
+    ```
+    >
+    > If you recently pushed your changes GitHub will automatically pop up a
+    > Compare & pull request button for any branches you recently pushed to.
+    > If you click that button it will automatically offer you to submit
+    > your pull-request to the confluentinc/cp-docker-images repository.
+    >
+    > -   Give your pull-request a meaningful title.
+    > -   In the description, explain your changes and the problem they are
+    >     solving.
+
+9.  Addressing code review comments
+
+    > Repeat steps 5. through 7. to address any code review comments and
+    > rebase your changes if necessary.
+    >
+    > Push your updated changes to update the pull request
+    >
+    ```
+    $ git push origin \[\--force\] feature-xxx
+    ```
+    >
+    > --force may be necessary to overwrite your existing pull request in
+    > case your commit history was changed when performing the rebase.
+    >
+    > Note: Be careful when using \--force since you may lose data if you
+    > are not careful.
+    >
+    ```
+    $ git push origin \--force feature-xxx
+    ```