Add a build with CMake example to README and Introduction page

Summary: related to T13767

Reviewers: ivica

Reviewed By: ivica

Subscribers: miljen, iljazovic

Differential Revision: https://repo.mireo.local/D29243

README.md

@@ -66,8 +66,7 @@ The following example illustrates a simple scenario of configuring a Client and
 int main() {
 	boost::asio::io_context ioc;
 
-	using client_type = async_mqtt5::mqtt_client<boost::asio::ip::tcp::socket>;
+	async_mqtt5::mqtt_client<boost::asio::ip::tcp::socket> c(ioc);
-	client_type c(ioc);
 
 	c.credentials("<your-client-id>", "<client-username>", "<client-pwd>")
 		.brokers("<your-mqtt-broker>", 1883)
@@ -85,7 +84,27 @@ int main() {
 	ioc.run();
 }
 ```
-To see more examples, visit [Examples](https://spacetime.mireo.com/async-mqtt5/async_mqtt5/examples.html).
+To see more examples, visit [Examples](https://github.com/mireo/async-mqtt5/tree/master/example).
+
+Building with CMake
+---------
+You can use the `CMakeLists.txt` provided in our repository to compile and run any of the [examples](https://github.com/mireo/async-mqtt5/tree/master/example) or your own source files. 
+The following commands demonstrate compiling and running the previous code using CMake.
+The source file is located at [example/hello_world_over_tcp.cpp](https://github.com/mireo/async-mqtt5/blob/master/example/hello_world_over_tcp.cpp).
+
+```console
+	# navigate to the root folder of Async.MQTT5
+
+	# compile the example
+	cmake -S . -B {build-folder} -DBUILD_EXAMPLES=ON -DCMAKE_EXE_LINKER_FLAGS="-pthread"
+	cmake --build {build-folder}
+
+	# run the example
+	./{build-folder}/example/example
+```
+
+You can edit the [example/CMakeLists.txt](https://github.com/mireo/async-mqtt5/blob/master/example/CMakeLists.txt) file to compile the source file of your choice.
+By default, it will compile [example/hello_world_over_tcp.cpp](https://github.com/mireo/async-mqtt5/blob/master/example/hello_world_over_tcp.cpp).
 
 When to use
 ---------

doc/qbk/00_main.qbk

@@ -20,7 +20,7 @@
 [template indexterm1[term1] '''<indexterm><primary>'''[term1]'''</primary></indexterm>''']
 [template indexterm2[term1 term2] '''<indexterm><primary>'''[term1]'''</primary><secondary>'''[term2]'''</secondary></indexterm>''']
 
-[template ghreflink[path text] [@https://github.com/mireo/async-mqtt5/[path] [text]]]
+[template ghreflink[path text] [@https://github.com/mireo/async-mqtt5/blob/master/[path] [text]]]
 [template reflink2[id text][link async_mqtt5.ref.[id] [^[text]]]]
 [template reflink[id][reflink2 [id] [id]]]
 [template refmem[class mem][reflink2 [class].[mem] [class]::[mem]]]

doc/qbk/01_intro.qbk

@@ -59,8 +59,7 @@ The following example illustrates a simple scenario of configuring a Client and
 	int main() {
 		boost::asio::io_context ioc;
 
-		using client_type = async_mqtt5::mqtt_client<boost::asio::ip::tcp::socket>;
+		async_mqtt5::mqtt_client<boost::asio::ip::tcp::socket> c(ioc);
-		client_type c(ioc);
 
 		c.credentials("<your-client-id>", "<client-username>", "<client-pwd>")
 			.brokers("<your-mqtt-broker>", 1883)
@@ -80,6 +79,23 @@ The following example illustrates a simple scenario of configuring a Client and
 
 To see more examples, visit [link async_mqtt5.examples Examples].
 
+[heading Building with CMake]
+You can use the `CMakeLists.txt` provided in our repository to compile and run any of the [link async_mqtt5.examples examples] or your own source files.
+The following commands demonstrate compiling and running the previous code using CMake. 
+The source file is located at [ghreflink example/hello_world_over_tcp.cpp example/hello_world_over_tcp.cpp].
+
+	# navigate to the root folder of Async.MQTT5
+
+	# compile the example
+	cmake -S . -B {build-folder} -DBUILD_EXAMPLES=ON -DCMAKE_EXE_LINKER_FLAGS="-pthread"
+	cmake --build {build-folder}
+
+	# run the example
+	./{build-folder}/example/example
+
+You can edit the [ghreflink example/CMakeLists.txt example/CMakeLists.txt] file to compile the source file of your choice.
+By default, it will compile [ghreflink example/hello_world_over_tcp.cpp example/hello_world_over_tcp.cpp].
+
 [heading When to use]
 
 __Self__ might be suitable for you if any of the following statements is true:

example/hello_world_over_tcp.cpp

@@ -14,12 +14,12 @@ int main() {
 	async_mqtt5::mqtt_client<boost::asio::ip::tcp::socket> client(ioc);
 
 	// 1883 is the default TCP MQTT port.
-	client.brokers("<your-mqtt-broker>", 1883)
+	client.brokers("broker.hivemq.com", 1883)
 		.async_run(boost::asio::detached);
 
 	client.async_publish<async_mqtt5::qos_e::at_most_once>(
-		"<topic>", "Hello world!",
+		"async-mqtt5/test", "Hello world!",
-		async_mqtt5::retain_e::no, async_mqtt5::publish_props {},
+		async_mqtt5::retain_e::yes, async_mqtt5::publish_props {},
 		[&client](async_mqtt5::error_code ec) {
 			std::cout << ec.message() << std::endl;
 			client.async_disconnect(boost::asio::detached);