readme update

README.md

@@ -1 +1,16 @@
-The whole library purpose is to simplify working with Czech VAT while it allows to extend and bend computing logic of every important operation.
+The whole library purpose is to simplify working with Czech VAT while it allows to extend and bend computing logic of every important operation.
+
+```php
+$cl = new \BiteIT\Taxes\CalcLogic();
+
+$pl = new \BiteIT\Taxes\PriceList(\BiteIT\Taxes\Rates::HIGH_PERCENT, $cl);
+
+$pl->addWithVat(121, 1);
+$pl->addWithVat(200, 2, \BiteIT\Taxes\Rates::MEDIUM_PERCENT);
+$pl->addWithVat(299, 4, \BiteIT\Taxes\Rates::LOW_PERCENT);
+
+var_dump([
+ $pl->getTotalsWithVat(),
+ $pl->getTotalsWithoutVat()
+]);
+```