Add Complementary Project - create-mui-theme (#12269)

Introduce `create-mui-theme`, an online tool allowing to create color palettes via https://material.io/tools/color and turn them into Material-UI themes.
Demo: https://react-theming.github.io/create-mui-theme/
Source: https://github.com/react-theming/create-mui-theme

docs/src/pages/discover-more/related-projects/related-projects.md

@@ -20,6 +20,7 @@ Feel free to submit a pull request to add more projects; we will accept them if
 
 ## Complementary Projects
 
+- [create-mui-theme](https://react-theming.github.io/create-mui-theme/) Online tool for creating Material-UI themes via Material Design Color Tool
 - [react-admin](https://github.com/marmelab/react-admin) An admin framework combining material-ui with Redux, redux-form, redux-saga, and recompose
 - [react-autosuggest](https://github.com/moroshko/react-autosuggest) WAI-ARIA compliant React autosuggest component.
 - [react-final-form](https://github.com/final-form/react-final-form#material-ui-10) Subscription-based form state management for React.