Add documentation [skip ci]

Author: z4kn4fein

README.md

@@ -1,2 +1,57 @@
 # php-semver
-Semantic version parser and comparator for PHP
+[![Build Status](https://travis-ci.com/z4kn4fein/php-semver.svg?branch=master)](https://travis-ci.com/z4kn4fein/php-semver)
+[![Coverage Status](https://img.shields.io/codecov/c/github/z4kn4fein/php-semver.svg)](https://codecov.io/gh/z4kn4fein/php-semver)
+[![Latest Stable Version](https://poser.pugx.org/z4kn4fein/php-semver/version)](https://packagist.org/packages/z4kn4fein/php-semver)
+[![Total Downloads](https://poser.pugx.org/z4kn4fein/php-semver/downloads)](https://packagist.org/packages/z4kn4fein/php-semver)
+[![Latest Unstable Version](https://poser.pugx.org/z4kn4fein/php-semver/v/unstable)](https://packagist.org/packages/z4kn4fein/php-semver)
+
+Semantic version utility library with parser and comparator written in PHP. It provides full support for the [semver 2.0.0](https://semver.org/spec/v2.0.0.html) standards. 
+
+## Requirements
+[PHP](https://www.php.net/) >= 5.5
+
+## Installation with [Composer](https://getcomposer.org/)
+```shell
+composer require z4kn4fein/php-semver
+```
+
+## Usage
+#### Parsing and available properties
+```php
+<?php
+
+use z4kn4fein\SemVer\Version;
+
+$version = Version::parse('2.5.6-alpha.12+build.34');
+
+echo $version->getMajor();          // 2
+echo $version->getMinor();          // 5
+echo $version->getPatch();          // 6
+echo $version->getPreRelease();     // alpha.12
+echo $version->getBuildMeta();      // build.34
+echo $version->getVersionString();  // 2.5.6-alpha.12+build.34
+```
+#### Compare two versions
+```php
+<?php
+
+use z4kn4fein\SemVer\Version;
+
+// with static methods
+echo Version::lessThan('2.3.4', '2.4.1');                    // true
+echo Version::lessThanOrEqual('2.4.1', '2.4.1');             // true
+echo Version::greaterThan('2.3.1-alpha.5', '2.3.1-alpha.3'); // true
+echo Version::greaterThanOrEqual('3.2.3','3.2.2');           // true
+echo Version::equal('3.2.3','3.2.3+build.3');                // true
+
+// with instance methods
+$version = Version::parse('2.5.6-alpha.12+build.34');
+
+echo $version->isLessThan('2.3.1');                  // false
+echo $version->isLessThanOrEqual('2.5.6-alpha.15');  // true
+echo $version->isGreaterThan('2.5.6');               // false
+echo $version->isLessThanOrEqual('2.5.6-alpha.12');  // true
+echo $version->isEqual('2.5.6-alpha.12+build.56');   // true
+```
+## Invalid version handling
+When the version parsing fails due to an invalid format, the library throws a specific `VersionFormatException`.

composer.json

@@ -1,7 +1,7 @@
 {
   "name": "z4kn4fein/php-semver",
   "type": "library",
-  "description": "Semantic version parser and comparator for PHP.",
+  "description": "Semantic version utility library with parser and comparator written in PHP. It provides full support for the semver 2.0.0 standards.",
   "minimum-stability": "stable",
   "keywords": ["Semantic version", "semver", "semver-parsing", "semver-compare"],
   "homepage": "https://github.com/z4kn4fein/php-semver",