fix: remove broken/dead tutorial links (fixes #900)

- Remove thinkster.io links (domain no longer resolves)
- Remove sahatyalkabov.com character voting tutorial (404)
- Remove dev.stephendiehl.com/fun Haskell tutorial (connection timed out)

Author: ZhouYinLong-lab

README.md

@@ -233,7 +233,6 @@ To get started, simply fork this repo. Please refer to [CONTRIBUTING.md](CONTRIB
 
 - [Create Serverless React.js Apps](http://serverless-stack.com/)
 - [Create a Trello Clone](http://codeloveandboards.com/blog/2016/01/04/trello-tribute-with-phoenix-and-react-pt-1/)
-- [Create a Character Voting App with React, Node, MongoDB and SocketIO](http://sahatyalkabov.com/create-a-character-voting-app-using-react-nodejs-mongodb-and-socketio)
 - [React Tutorial: Cloning Yelp](https://www.fullstackreact.com/articles/react-tutorial-cloning-yelp/)
 - [Build a Full Stack Movie Voting App with Test-First Development using Mocha, React, Redux and Immutable](https://teropa.info/blog/2015/09/10/full-stack-redux-tutorial.html)
 - [Build A Simple Medium Clone using React.js and Node.js](https://medium.com/@kris101/clone-medium-on-node-js-and-react-js-731cdfbb6878)
@@ -271,7 +270,6 @@ To get started, simply fork this repo. Please refer to [CONTRIBUTING.md](CONTRIB
 - Build an offline-capable Hacker News client with Angular 2+
   - [Part 1](https://houssein.me/angular2-hacker-news)
   - [Part 2](https://houssein.me/progressive-angular-applications)
-- [Build a Google+ clone with Django and AngularJS (Angular 1.x)](https://thinkster.io/django-angularjs-tutorial)
 - Build A Beautiful Real World App with Angular 8 :
 
   - [Part I](https://medium.com/@hamedbaatour/build-a-real-world-beautiful-web-app-with-angular-6-a-to-z-ultimate-guide-2018-part-i-e121dd1d55e)
@@ -612,7 +610,6 @@ To get started, simply fork this repo. Please refer to [CONTRIBUTING.md](CONTRIB
 
 ## Haskell:
 
-- [Write You a Haskell - Build a modern functional compiler](http://dev.stephendiehl.com/fun/)
 - [Write Yourself a Scheme in 48 hours](https://en.wikibooks.org/wiki/Write_Yourself_a_Scheme_in_48_Hours)
 - [Write You A Scheme, Version 2](https://github.com/adamwespiser/scheme)
 - [Roll Your Own IRC Bot](https://wiki.haskell.org/Roll_your_own_IRC_bot)
@@ -670,7 +667,6 @@ To get started, simply fork this repo. Please refer to [CONTRIBUTING.md](CONTRIB
 - [Exercism](http://www.exercism.io/)
 - [Egghead.io](http://www.egghead.io/)
 - [Michael Herman's Blog](http://mherman.org/)
-- [Thinkster.io](http://thinkster.io)
 - [Enlight](https://enlight.nyc/)
 - [Hack Club Workshops](https://hackclub.com/workshops/)
 - [CodeCrafters](https://codecrafters.io/)