Added financial contributors to the README

README.md

@@ -1,7 +1,7 @@
 ![php-excel](resource/logo.png)
 
 [![Build Status](https://travis-ci.org/viest/php-ext-xlswriter.svg?branch=master)](https://travis-ci.org/viest/php-ext-xlswriter)
-[![Build status](https://ci.appveyor.com/api/projects/status/w4cfjo9e4gsrs6rn/branch/master?svg=true)](https://ci.appveyor.com/project/viest/php-ext-excel-export/branch/master)
+[![Financial Contributors on Open Collective](https://opencollective.com/php-ext-xlswriter/all/badge.svg?label=financial+contributors)](https://opencollective.com/php-ext-xlswriter) [![Build status](https://ci.appveyor.com/api/projects/status/w4cfjo9e4gsrs6rn/branch/master?svg=true)](https://ci.appveyor.com/project/viest/php-ext-excel-export/branch/master)
 [![](https://img.shields.io/github/release/viest/php-ext-excel-export.svg)](https://github.com/viest/php-ext-xlswriter)
 [![](https://img.shields.io/badge/PHP-%3E%3D%207.0-brightgreen.svg)](https://github.com/viest/php-ext-xlswriter)
 [![](https://img.shields.io/github/contributors/viest/php-ext-excel-export.svg)](https://github.com/viest/php-ext-xlswriter)
@@ -76,6 +76,36 @@ composer require viest/php-ext-xlswriter-ide-helper:dev-master
 
 <img width="160" src="resource/qq.jpg"/>
 
+## Contributors
+
+### Code Contributors
+
+This project exists thanks to all the people who contribute. [[Contribute](CONTRIBUTING.md)].
+<a href="https://github.com/viest/php-ext-xlswriter/graphs/contributors"><img src="https://opencollective.com/php-ext-xlswriter/contributors.svg?width=890&button=false" /></a>
+
+### Financial Contributors
+
+Become a financial contributor and help us sustain our community. [[Contribute](https://opencollective.com/php-ext-xlswriter/contribute)]
+
+#### Individuals
+
+<a href="https://opencollective.com/php-ext-xlswriter"><img src="https://opencollective.com/php-ext-xlswriter/individuals.svg?width=890"></a>
+
+#### Organizations
+
+Support this project with your organization. Your logo will show up here with a link to your website. [[Contribute](https://opencollective.com/php-ext-xlswriter/contribute)]
+
+<a href="https://opencollective.com/php-ext-xlswriter/organization/0/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/0/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/1/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/1/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/2/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/2/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/3/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/3/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/4/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/4/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/5/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/5/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/6/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/6/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/7/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/7/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/8/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/8/avatar.svg"></a>
+<a href="https://opencollective.com/php-ext-xlswriter/organization/9/website"><img src="https://opencollective.com/php-ext-xlswriter/organization/9/avatar.svg"></a>
+
 #### License
 
 FreeBSD license