Add tmate

Author: tharun571

.github/workflows/main.yml

@@ -134,6 +134,11 @@ jobs:
           cd build\test
           .\test_xeus_cpp.exe
 
+      - name: Setup tmate session
+        uses: mxschmitt/action-tmate@v3
+        # When debugging increase to a suitable value!
+        timeout-minutes: 30
+
       - name: Python tests Unix Systems
         if: ${{ runner.os != 'windows' }}
         shell: bash -l {0}