Replace 50 Shades of Go with 100 Go Mistakes (#272)

Fixes #270

Author: pellared

README.md

@@ -39,7 +39,7 @@ See [Go Books](https://github.com/dariubs/GoBooks) for a list of books, both fre
 - [Channel Axioms](https://dave.cheney.net/2014/03/19/channel-axioms)
 - [Golang channels tutorial](https://guzalexander.com/2013/12/06/golang-channels-tutorial.html)
 - [Common Gotchas in Go](https://divan.dev/posts/avoid_gotchas/)
-- [50 Shades of Go: Traps, Gotchas, and Common Mistakes for New Golang Devs](https://devs.cloudimmunity.com/gotchas-and-common-mistakes-in-go-golang/)
+- [100 Go Mistakes and How to Avoid Them](https://100go.co)
 - [Slices from the ground up](https://dave.cheney.net/2018/07/12/slices-from-the-ground-up)
 - [6 Tips for Using Strings in Go](https://www.calhoun.io/6-tips-for-using-strings-in-go/)
 - [Go Defer Simplified with Practical Visuals](https://blog.learngoprogramming.com/golang-defer-simplified-77d3b2b817ff)