Merge pull request #563 from neerdoc/3rd-party

Added list of 3rd party applications.

docs/examples.md

@@ -8,3 +8,8 @@ Running `doorstop` in Docker: [tlwt/doorstop-docker](https://github.com/tlwt/doo
 
 - **[ros-safety/requirements-playground](https://github.com/ros-safety/requirements-playground)**: This is a small repo for demonstrating how Doorstop can be used to manage requirements in a C++ project.
 - **[urbasus/literate-programming-in-doorstop](https://github.com/urbasus/literate-programming-in-doorstop)**: Proof-of-concept for combining Doorstop and Literate Programming.
+
+# 3rd-party clients
+
+- **[doorframe](https://doorframe.io/)**: This is (closed source) GitHub App that uses Doorstop as backend.
+- **[sevendays/doorhole](https://github.com/sevendays/doorhole)**: This is standalone GUI for Doorstop.