Update README.md

README.md

@@ -10,19 +10,39 @@ The recommended way to install PhpInvariant is through Composer
 
 # Quick start example
 1. Create a folder `invariants`
-2. Create class SimpleTest inside this folder
+2. Create Test class inside this folder
+3. Run command `vendor/bin/phpinvariant run --dir=invariants`
+
+# How to write invariant test
+Rules:  
+1. Сlass name must end with 'Test'
+1. Class must extends `BaseInvariantTest`
+1. Each public method with a name 'test...' will be launched
+
+## Generators
+Generators generate random data for invariants checking. To use a generator for a variable write the attribute for variable  
+
+## Finish conditions
+These conditions are used to determine when to end the test execution. To determine finish condition  write the attribute for test method
+
+## Example
+
 ```php
 class SimpleTest extends BaseInvariantTest
 {
     #[FinishCount(10)]
-    public function testDivision(#[IntegerGenerator(99, 101)] int $x)
+    public function testDivision(#[IntegerGenerator(50, 101)] int $x)
     {
         // fail when $x=101
         $this->assertTrue($x < 100);
     }
 }
 ```
-3. Run command `vendor/bin/phpinvariant run --dir=invariants`
+Explanation:  
+* `#[FinishCount(10)]` - run test 10 times
+* `#[IntegerGenerator(50, 101)] int $x` - randomly generate integer `$x` in [50, 101]
+
+
+
 
-# Documentation