Added backers and sponsors on the README

Author: monkeywithacupcake

README.md

@@ -1,4 +1,4 @@
-[![NuGet Version](http://img.shields.io/nuget/v/GeoJSON.NET.svg?style=flat)](https://www.nuget.org/packages/GeoJSON.NET/) 
+[![Backers on Open Collective](https://opencollective.com/geojson-net/backers/badge.svg)](#backers) [![Sponsors on Open Collective](https://opencollective.com/geojson-net/sponsors/badge.svg)](#sponsors) [![NuGet Version](http://img.shields.io/nuget/v/GeoJSON.NET.svg?style=flat)](https://www.nuget.org/packages/GeoJSON.NET/) 
 [![Build status](https://ci.appveyor.com/api/projects/status/i5afnui06gqco0wi/branch/master?svg=true)](https://ci.appveyor.com/project/GeojsonNet/geojson-net/branch/master)
 
 # GeoJSON.NET
@@ -43,3 +43,33 @@ This library would be NOTHING without its [contributors](https://github.com/GeoJ
  We have the awesome .NET tools from [JetBrains](http://www.jetbrains.com/).
 
 [![Resharper](http://www.filehelpers.net/images/tools_resharper.gif)](http://www.jetbrains.com/resharper/)
+
+## Contributors
+
+This project exists thanks to all the people who contribute. 
+<a href="https://github.com/GeoJSON-Net/GeoJSON.Net/graphs/contributors"><img src="https://opencollective.com/geojson-net/contributors.svg?width=890&button=false" /></a>
+
+
+## Backers
+
+Thank you to all our backers! 🙏 [[Become a backer](https://opencollective.com/geojson-net#backer)]
+
+<a href="https://opencollective.com/geojson-net#backers" target="_blank"><img src="https://opencollective.com/geojson-net/backers.svg?width=890"></a>
+
+
+## Sponsors
+
+Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [[Become a sponsor](https://opencollective.com/geojson-net#sponsor)]
+
+<a href="https://opencollective.com/geojson-net/sponsor/0/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/0/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/1/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/1/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/2/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/2/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/3/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/3/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/4/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/4/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/5/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/5/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/6/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/6/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/7/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/7/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/8/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/8/avatar.svg"></a>
+<a href="https://opencollective.com/geojson-net/sponsor/9/website" target="_blank"><img src="https://opencollective.com/geojson-net/sponsor/9/avatar.svg"></a>
+
+