Add note about sponsoring options. (#13616)

* Add note about sponsoring options.

* Fix linting

docs/index.md

@@ -8,7 +8,7 @@
 [![npm version](https://badgen.net/npm/v/sequelize)](https://www.npmjs.com/package/sequelize)
 [![Build Status](https://github.com/sequelize/sequelize/workflows/CI/badge.svg)](https://github.com/sequelize/sequelize/actions?query=workflow%3ACI)
 [![npm downloads](https://badgen.net/npm/dm/sequelize)](https://www.npmjs.com/package/sequelize)
-<!-- [![codecov](https://badgen.net/codecov/c/github/sequelize/sequelize?icon=codecov)](https://codecov.io/gh/sequelize/sequelize) -->
+[![sponsor](https://img.shields.io/opencollective/all/sequelize?label=sponsors)](https://opencollective.com/sequelize)
 [![Last commit](https://badgen.net/github/last-commit/sequelize/sequelize)](https://github.com/sequelize/sequelize)
 [![Merged PRs](https://badgen.net/github/merged-prs/sequelize/sequelize)](https://github.com/sequelize/sequelize)
 [![GitHub stars](https://badgen.net/github/stars/sequelize/sequelize)](https://github.com/sequelize/sequelize)
@@ -46,3 +46,9 @@ User.init({
 ```
 
 To learn more about how to use Sequelize, read the tutorials available in the left menu. Begin with [Getting Started](manual/getting-started.html).
+
+## Supporting the project
+
+Do you like Sequelize and would like to give back to the engineering team behind it?
+
+We have recently created an [OpenCollective based money pool](https://opencollective.com/sequelize) which is shared amongst all core maintainers based on their contributions. Every support is wholeheartedly welcome. ❤️