Added heavy work example

https_examples.cpp

@@ -87,6 +87,17 @@ int main() {
         *response << "HTTP/1.1 200 OK\r\nContent-Length: " << number.length() << "\r\n\r\n" << number;
     };
     
+    //Get example simulating heavy work in a separate thread
+    server.resource["^/work$"]["GET"]=[&server](shared_ptr<HttpsServer::Response> response, shared_ptr<HttpsServer::Request> /*request*/) {
+        *response << "HTTP/1.1 200 OK\r\n";
+        thread work_thread([response] {
+            this_thread::sleep_for(chrono::seconds(5));
+            string message="Work done";
+            *response << "Content-Length: " << message.length() << "\r\n\r\n" << message;
+        });
+        work_thread.detach();
+    };
+    
     //Default GET-example. If no other matches, this anonymous function will be called. 
     //Will respond with content in the web/-directory, and its subdirectories.
     //Default file: index.html