Initial set of docs for forking

docs/technical-setup/fork-the-repo.md

@@ -0,0 +1,36 @@
+# Fork the repository
+
+You will need to create a [_fork_](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/fork-a-repo#about-forks) of the [`OpenScPCA-analysis`](https://github.com/AlexsLemonade/OpenScPCA-analysis/) repository.
+
+A fork is a copy of an _upstream_ repository (here, `AlexsLemonade/OpenScPCA-analysis` is the _upstream_) that you will own and will be in your GitHub account.
+As a contributor, you will perform analyses in your fork.
+
+<!-- Is this too much? -->
+One benefit of using a fork is that changes you make will not affect the upstream project in `AlexsLemonade/OpenScPCA-analysis`.
+This means you can safely work on your analyses without worrying about messing anything up in the upstream repository.
+Periodically, you will request to add your analysis code to the upstream repository through a _pull request_ process.
+
+
+## Create your fork
+
+Follow these steps to create your fork:
+
+1. In your browser, navigate to the `OpenScPCA-analysis` repository: [https://github.com/AlexsLemonade/OpenScPCA-analysis/](https://github.com/AlexsLemonade/OpenScPCA-analysis/).
+
+
+2. At the top right corner, click the "Fork" button:
+(The numbers you see in this screenshot may differ from the numbers on the website - that's ok!)
+![Button on GitHub.com to fork a repository.](../img/fork-button.png){width="400"} <!-- No new line above, to keep tabbed in -->
+
+
+1. On the next screen, GitHub will prompt you for some settings about your fork.
+Make sure that these conditions are met, and then click the "Create fork" button on the bottom right.
+    - Although the screenshot below shows an "Owner" username of `sjspielman`, you should see your username in this field.
+    - Keep the default Repository name as `OpenScPCA-analysis`.
+    - The box "Copy the `main` branch only" is checked
+    - You can add a description if you want, but it is not necessary.
+![Screen to set up new fork, showing .](../img/create-fork.png){width="600"} <!-- No new line above, to keep tabbed in -->
+
+
+1. That's it! 🎉
+In a few moments, GitHub will redirect to your newly forked repository at `https://github.com/YOUR_USERNAME/OpenScPCA-analysis`, and you're ready to proceed to the next step of [cloning your repository](./clone-the-repo.md).