Add donation section to readme.

[skip ci]

CHANGELOG.md

@@ -5,6 +5,7 @@ Exclamation symbols (:exclamation:) note something of importance e.g. breaking c
 
 ## [Unreleased]
 ### Added
+- Donation section and links in readme.
 ### Changed
 - Updated and optimised all DB classes, removing a lot of bulky code.
 ### Deprecated

README.md

 # PHP Telegram Bot
 
 [![Join the bot support group on Telegram](https://img.shields.io/badge/telegram-@PHP__Telegram__Bot__Support-32a2da.svg)](https://telegram.me/PHP_Telegram_Bot_Support)
+[![Donate](https://img.shields.io/badge/%F0%9F%92%99-Donate-blue.svg)](#donate)
 
 [![Build Status](https://travis-ci.org/php-telegram-bot/core.svg?branch=master)](https://travis-ci.org/php-telegram-bot/core)
 [![Code Coverage](https://img.shields.io/scrutinizer/coverage/g/php-telegram-bot/core/develop.svg?style=flat-square)](https://scrutinizer-ci.com/g/php-telegram-bot/core/?b=develop)
@@ -53,6 +54,7 @@ A Telegram Bot based on the official [Telegram Bot API][Telegram-Bot-API]
 - [Projects with this library](#projects-with-this-library)
 - [Troubleshooting](#troubleshooting)
 - [Contributing](#contributing)
+- [Donate](#donate)
 - [License](#license)
 - [Credits](#credits)
 
@@ -573,6 +575,19 @@ If you like living on the edge, please report any bugs you find on the
 
 See [CONTRIBUTING](.github/CONTRIBUTING.md) for more information.
 
+## Donate
+
+All work on this bot consists of many hours of coding during our free time, to provide you with a Telegram Bot library that is easy to use and extend.
+If you enjoy using this library and would like to say thank you, donations are a great way to show your support.
+
+Donations are invested back into the project :+1:
+
+- Gratipay: [Gratipay/PHP-Telegram-Bot]
+- Liberapay: [Liberapay/PHP-Telegram-Bot]
+- PayPal: [PayPal/noplanman] (account of @noplanman)
+- Bitcoin: [166NcyE7nDxkRPWidWtG1rqrNJoD5oYNiV][bitcoin]
+- Ethereum: [0x485855634fa212b0745375e593fAaf8321A81055][ethereum]
+
 ## License
 
 Please see the [LICENSE](LICENSE.md) included in this repository for a full copy of the MIT license,
@@ -600,3 +615,8 @@ Credit list in [CREDITS](CREDITS)
 [wiki]: https://github.com/php-telegram-bot/core/wiki "PHP Telegram Bot Wiki"
 [wiki-create-your-own-commands]: https://github.com/php-telegram-bot/core/wiki/Create-your-own-commands "Create your own commands"
 [issues]: https://github.com/php-telegram-bot/core/issues "PHP Telegram Bot Issues"
+[Gratipay/PHP-Telegram-Bot]: https://gratipay.com/PHP-Telegram-Bot "Donate with Gratipay"
+[Liberapay/PHP-Telegram-Bot]: https://liberapay.com/PHP-Telegram-Bot "Donate with Liberapay"
+[PayPal/noplanman]: https://paypal.me/noplanman "Donate with PayPal"
+[bitcoin]: bitcoin:166NcyE7nDxkRPWidWtG1rqrNJoD5oYNiV "Donate with Bitcoin"
+[ethereum]: https://www.myetherwallet.com/?to=0x485855634fa212b0745375e593fAaf8321A81055 "Donate with Ethereum"