Add Details to Contributor Guide About Forking/PRs

doc/contributing.md

@@ -84,6 +84,41 @@ This is a guide for how to install PyRIT into a `conda` environment.
     az login
     ```
 
+## Set Up: Contribute with Git
+
+Before creating your first pull request, set up your fork to contribute to PyRIT by following these steps:
+
+1. [Fork](https://github.com/Azure/PyRIT/fork) the repo from the main branch. By default, forks are named the same as their upstream repository. This will create a new repo called `GITHUB_USERNAME/PyRIT` (where `GITHUB_USERNAME` is a variable for your GitHub username).
+2. Add this new repo locally wherever you cloned PyRIT
+```
+# to see existing remotes
+git remote -v
+
+# add your fork as a remote named `REMOTE_NAME`
+git remote add REMOTE_NAME https://github.com/GITHUB_USERNAME/PyRIT.git
+```
+
+To add your contribution to the repo, the flow typically looks as follows:
+```
+git checkout main
+git pull # pull from origin
+git checkout -b mybranch
+
+... # make changes
+
+git add .
+git commit -m "changes were made"
+git push REMOTE_NAME
+```
+
+After pushing changes, you'll see a link to create a PR:
+```
+remote: Create a pull request for 'mybranch' on GitHub by visiting:
+remote:      https://github.com/GITHUB_USERNAME/PyRIT/pull/new/mybranch
+```
+
+See more on [creating a pull request from a fork](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).
+
 ## Dev Resources
 
 ### Environment Setup