Copy the weaver contrib guide over to weaver-gke. (#8)

CONTRIBUTING.md

@@ -7,10 +7,9 @@ We'd love to accept your patches and contributions to this project.
 ### Sign our Contributor License Agreement
 
 Contributions to this project must be accompanied by a
-[Contributor License Agreement](https://cla.developers.google.com/about) (CLA).
-You (or your employer) retain the copyright to your contribution; this simply
-gives us permission to use and redistribute your contributions as part of the
-project.
+[Contributor License Agreement][cla] (CLA). You (or your employer) retain the
+copyright to your contribution; this simply gives us permission to use and
+redistribute your contributions as part of the project.
 
 If you or your current employer have already signed the Google CLA (even if it
 was for a different project), you probably don't need to do it again.
@@ -25,9 +24,109 @@ Guidelines](https://opensource.google/conduct/).
 
 ## Contribution process
 
+Here is a detailed outline of the steps needed to make changes to the Service
+Weaver GKE deployer.
+
+1. Clone the repository.
+
+   ```shell
+   git clone [email protected]:ServiceWeaver/weaver-gke.git
+   cd weaver-gke
+   ```
+
+   If you have already cloned the repository for previous changes,
+   you can reuse it, but make sure to first pull any recent changes
+   to the GKE deployer:
+
+   ```shell
+   cd weaver-gke
+   git switch main
+   git pull origin main
+   ```
+
+2. Make a local branch in your clone.
+
+   ```shell
+   git switch -c my_branch  # Pick a name appropriate to your work
+   ```
+
+3. Make changes and commit to local branch.
+
+   ```shell
+   # ... editing, testing, ... 
+   git commit ...
+   ```
+
+   If you need to make multiple commits (e.g., if you checkpoint as
+   you work), consider using `git commit --amend` or some other git
+   command to keep all of your changes in a single commit.
+
+4. Pull any changes that may have been made in the shared repository
+   main branch.
+
+   ```shell
+   git switch my_branch
+   git pull --rebase origin main
+   ```
+
+   Note that this command may result in merge conflicts. Fix those if
+   needed.
+
+5. Push your branch to the corresponding branch in the shared repository.
+
+   ```shell
+   git switch my_branch
+   git push -u origin my_branch
+   ```
+
+6. Select the branch you are working on in the drop-down menu of branches on
+   https://github.com/ServiceWeaver/weaver-gke . Then hit the `Compare and pull
+   request` button.
+
+7. Respond to feedback, which may involve making new commits or
+   updating your prior commits. If you made any changes, push them
+   to github again. If you amended a commit, you will have to force
+   the push.
+
+   ```shell
+   git switch my_branch
+   git push --force
+   ```
+
+8. Once reviewers are happy, pull any main branch changes that may
+   have happened since step 4.
+
+   ```shell
+   git switch my_branch
+   git pull --rebase origin main
+   ```
+
+   If you made multiple commits, squash them together if you wish
+   (typically using an interactive rebase).
+
+   If you picked up new changes or made any changes, push your branch
+   again to github, as described in step 7.
+
+9. Ask somebody who has permissions (or do it yourself if you
+   have permissions) to merge your branch into the main branch
+   of the shared repository. The reviewer may do this without
+   being asked.
+
+   Select the `Rebase and merge` option on https://github.com/ServiceWeaver/weaver-gke
+   or use the command line instructions found on that page.
+
 ### Code Reviews
 
 All submissions, including submissions by project members, require review. We
-use GitHub pull requests for this purpose. Consult
-[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
-information on using pull requests.
+use GitHub pull requests for this purpose. Consult [GitHub Help][github_help]
+for more information on using pull requests.
+
+To make sure changes are well coordinated, we ask you to discuss any significant
+change prior to sending a pull request. To do so, either file a
+[new issue][new_issue] or claim an [existing one][issues].
+
+[cla]: https://cla.developers.google.com/about
+[github_help]: https://help.github.com/articles/about-pull-requests/
+[new_issue]: https://github.com/ServiceWeaver/weaver-gke/issues/new
+[issues]: https://github.com/ServiceWeaver/weaver-gke/issues
+