Added workdir support for docker exec

Author: Jordan Walsh

docs/schema/vimspector.schema.json

@@ -186,6 +186,10 @@
                           "type": "array",
                           "items": { "type": "string" },
                           "description": "A single command to execute for remote-launch. Like runCommands but for a single command."
+                        },
+                        "workdir": {
+                          "type": "string",
+                          "description": "For containers. The value passed to docker exec for the working directory."
                         }
                       }
                     }