add debug launcher for the app

Author: gilesknap

.vscode/launch.json

@@ -4,6 +4,12 @@
     // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
     "version": "0.2.0",
     "configurations": [
+        {
+            "name": "DLS PMAC Control",
+            "type": "debugpy",
+            "request": "launch",
+            "module": "dls_pmac_control"
+        },
         {
             "name": "Debug Unit Test",
             "type": "debugpy",