Update documentation

.docs/README.md

@@ -5,35 +5,16 @@ Usage
 
 ### Create instance of class
 
-If you leave the first parameter blank, the cache will be disabled.
-
-```php
-$cnb = new CnbApi\CnbApi(string $tempDirectory = null);
-```
-
-
-If you want to turn on caching results, use the first parameter to set the folder to temp folder.
-
 ```php
-$cnb = new CnbApi\CnbApi(__DIR__ . '/temp');
-```
-
-To use the cache, you must have the [nette/caching](https://packagist.org/packages/nette/caching) package installed, which is not part of the mandatory packages.
-
-**The folder must exist, otherwise the application will end with an exception.**
-
-If you do not want to cach the result, you do not need to specify the first parameter.
-
-```php
-$cnb = new CnbApi\CnbApi();
+$client = new CnbApi\Client(?CnbApi\Caching\ICaching $caching = null, ?CnbApi\Source\ISource $source = null);
 ```
 
 ### Exchange rate list selection
 
 To select the entire exchange rate list, there is a method that returns the complete data from the Czech National Bank.
 
 ```php
-$cnb->getEntity();
+$client->getEntity(?DateTime $date = null);
 ```
 
 The **first parameter is the date of the exchange rate list** . If the date is not specified, the exchange rate list is selected at the current date.
@@ -45,41 +26,45 @@ The method returns an object `CnbApi\Entity\ExchangeRate`
 Select by exchange rate code
 
 ```php
-$cnb->findRateByCode('EUR');
+$client->findRateByCode('EUR');
 ```
 
 Select by country name
 
 ```php
-$cnb->findRateByCountry('Mexiko');
+$client->findRateByCountry('Mexiko');
 ```
 
 These selections always return the object `CnbApi\Entity\Rate`
 
 If you specify the DateTime object as the second parameter, the date will be listed with the date set. Time is ignored.
 
 ```php
-$cnb->findRateByCode('EUR', new \DateTime('2019-01-01'));
+$client->findRateByCode('EUR', new \DateTime('2019-01-01'));
 ```
 
-### Currency conversion between Czech crown
+### Helper classes
 
-Ancillary methods are available that allow the transfer between the Czech crown and the country's target name or the country's destination code.
+In class `CnbApi\Helpers\Currency` are maintained most widely used currency.
 
 ```php
-$cnb->convertFromCzk('EUR', 5.0);
+$client->findRateByCode(\CnbApi\Helpers\Currency::EURO);
 ```
 
-```php
-$cnb->convertToCzk('EUR', 5.0);
-```
+### Advanced conversion
 
-Methods return object `CnbApi\Entity\Rate`
+If you need to convert from one currency to another, it is possible to use the Client :: rate (...) method, which allows conversion between multiple currencies.
 
-### Helper classes
+The entire conversion process is shown in this diagram.
 
-In class `CnbApi\Helpers\Currency` are maintained most widely used currency.
+```
++----------------------------------+   +---------------------+   +---------------------+
+| Client::rate(from: EUR, to: USD) +---> Convert EUR to CZK  +--->  Convert CZK to USD |
++----------------------------------+   +---------------------+   +---------------------+
+```
+
+Convert 5 EUR to USD:
 
 ```php
-$cnb->findRateByCode(\CnbApi\Helpers\Currency::EURO)
+$client->rate('EUR', 'USD', 5);
 ```