Adds section on Github integration

Author: samclark2015

git.qmd

@@ -90,6 +90,11 @@ Positron provides a 3-way merge editor to help you resolve conflicts by choosing
 
 **Learn more:** [Merge conflicts in VS Code](https://code.visualstudio.com/docs/sourcecontrol/overview#_merge-conflicts)
 
+## Integration with Git platforms
+Positron includes the [GitHub](https://open-vsx.org/extension/vscode/github) and [GitHub Pull Requests and Issues](https://open-vsx.org/extension/GitHub/vscode-pull-request-github) extensions out of the box, which let you manage GitHub repositories, issues, and PRs directly from within Positron. You can learn more about bundled extensions on the [Extensions](extensions.qmd#included-extensions) page.
+
+Other platforms are not integrated by default, but similar features are available after installing extensions like [GitLab Workflow](https://open-vsx.org/extension/GitLab/gitlab-workflow) or [Atlassian: Jira & Bitbucket](https://open-vsx.org/extension/atlassian/atlascode). You can search in the [Extensions pane](extensions.qmd#accessing-extensions) to find other extensions for the Git platform you use.
+
 ## Additional Resources
 
 - [Introduction to Git in VS Code ](https://code.visualstudio.com/docs/sourcecontrol/intro-to-git): Comprehensive guide with screenshots and examples