[client][skip ci] Explain meaning of sendEvent, sendCommand methods.

Author: makasim

docs/client/quick_tour.md

@@ -16,6 +16,8 @@ $ composer require enqueue/simple-client enqueue/amqp-ext
 
 ## Configure
 
+The code below shows how to use simple client with AMQP transport. There are other [supported brokers](supported_brokers.md).
+
 ```php
 <?php
 use Enqueue\SimpleClient\SimpleClient;
@@ -27,25 +29,56 @@ $client = new SimpleClient('amqp:');
 
 ## Produce message
 
+There two types of message a client can produce: events and commands.
+Events are used to notify others about something, in other words it is an implementation of [publish-subscribe pattern](https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern), sometimes called "fire-and-forget" too.
+With events there is no way to get a reply as a producer is not aware of any subscribed consumers.
+Commands are used to request a job to be done. It is an implementation of one-to-one messaging pattern.
+A producer can request a reply from the consumer though it is up to the consumer whether send it or not. 
+
+Commands work inside the app [scope](message_examples.md#scope) where events work inside the app scope as well as on [message bus](message_bus.md) scope.      
+
+Send event examples:
+  
 ```php
 <?php
 
 /** @var \Enqueue\SimpleClient\SimpleClient $client */
 
-$client->send('a_bar_topic', 'aMessageData');
+$client->setupBroker();
+
+$client->sendEvent('user_updated', 'aMessageData');
 
 // or an array
 
-$client->send('a_bar_topic', ['foo', 'bar']);
+$client->sendEvent('order_price_calculated', ['foo', 'bar']);
 
 // or an json serializable object
-$client->send('a_bar_topic', new class() implements \JsonSerializable {
+$client->sendEvent('user_activated', new class() implements \JsonSerializable {
     public function jsonSerialize() {
         return ['foo', 'bar'];
     }
 });
 ```
 
+Send command examples:
+  
+```php
+<?php
+
+/** @var \Enqueue\SimpleClient\SimpleClient $client */
+
+$client->setupBroker();
+
+// accepts same type of arguments as sendEvent method
+$client->sendCommand('calculate_statistics', 'aMessageData');
+
+$reply = $client->sendCommand('build_category_tree', 'aMessageData', true);
+
+$replyMessage = $reply->receive(5000); // wait for reply for 5 seconds
+
+$replyMessage->getBody();
+```
+
 ## Consume messages
 
 ```php

docs/client/supported_brokers.md

@@ -1,5 +1,20 @@
 # Client. Supported brokers
 
+Here's the list of transports supported by Enqueue Client:
+
+| Transport           | Package                                                    |  DSN                            |
+|:-------------------:|:----------------------------------------------------------:|:-------------------------------:|
+| AMQP, RabbitMQ      | [enqueue/amqp-bunny](../transport/amqp_bunny.md)           | amqp: amqp+bunny:               |
+| AMQP, RabbitMQ      | [enqueue/amqp-lib](../transport/amqp_lib.md)               | amqp: amqp+lib:                 |
+| AMQP, RabbitMQ      | [enqueue/amqp-ext](../transport/amqp.md)                   | amqp: amqp+ext:                 |
+| Doctrine DBAL       | [enqueue/dbal](../transport/dbal.md)                       | mysql: pgsql: pdo_pgsql etc     |
+| Filesystem          | [enqueue/fs](../transport/fs.md)                           | file:///foo/bar                 |
+| Google PubSub       | [enqueue/gps](../transport/gps.md)                         | gps:                            |
+| Redis               | [enqueue/gps](../transport/redis.md)                       | redis:                          |
+| Amazon SQS          | [enqueue/sqs](../transport/sqs.md)                         | sqs:                            |
+| STOMP, RabbitMQ     | [enqueue/stomp](../transport/stomp.md)                     | stomp:                          |
+| Null                | [enqueue/null](../transport/null.md)                       | null:                           |
+
 Here's the list of protocols and Client features supported by them 
 
 | Protocol       | Priority | Delay    | Expiration | Setup broker | Message bus |
@@ -11,7 +26,8 @@ Here's the list of protocols and Client features supported by them
 | Filesystem     |   No     |    No    |    No      |     Yes      |     No      |
 | Redis          |   No     |    No    |    No      |  Not needed  |     No      |
 | Doctrine DBAL  |   Yes    |    Yes   |    No      |     Yes      |     No      |
-| AWS SQS        |   No     |    Yes   |    No      |     Yes      |   Not impl  |
+| Amazon SQS     |   No     |    Yes   |    No      |     Yes      |   Not impl  |
+| Google PubSub  | Not impl | Not impl |  Not impl  |     Yes      |   Not impl  |
 
 * \* Possible if a RabbitMQ delay plugin is installed.
 * \*\* Possible if topics (exchanges) are configured on broker side manually.

pkg/simple-client/SimpleClient.php

@@ -125,6 +125,8 @@ public function sendEvent($topic, $message)
     }
 
     /**
+     * @deprecated since 0.8.18 and will be removed in 0.9. Use sendEvent method instead
+     *
      * @param string       $topic
      * @param string|array $message
      * @param bool         $setupBroker