@Colin Robinson Thanks for using Microsoft Q&A platform.
Yes, that is correct you need to setup source control from Azure Synapse Studio through which you can associate your workspace with a Git repository, Azure DevOps or GitHub. Please refer to the documentation - Source control in Azure Synapse Studio for details.
Once configured you can provide your developers their own branch to perform shared development by submitting pull requests from their respective branches to the collaboration branch and can later publish changes to Synapse service. Please find below the screenshot (Here I have enabled the repository with GitHub) submitted a pull request to merge from Dev branch to Main.
Please let me know if you have any other questions.