Add the practical go lessons from Dave Cheney (#10966)

* Add the practical go lessons from Dave Cheney

* Fix linter error

* Fix linter error

books/free-programming-books-langs.md

@@ -840,6 +840,7 @@ Books on general-purpose programming that don't focus on a specific language are
 * [Let's learn Go!](http://go-book.readthedocs.io/en/latest/)
 * [Practical Cryptography With Go](https://leanpub.com/gocrypto/read) - Kyle Isom
 * [Practical Go Lessons](https://www.practical-go-lessons.com) - Maximilien Andile
+* [Practical Go: Real world advice for writing maintainable Go programs](https://dave.cheney.net/practical-go/presentations/qcon-china.html) - Dave Cheney (HTML)
 * [Production Go](https://leanpub.com/productiongo/read) - Herman Schaaf and Shawn Smith (EPUB, HTML, PDF) (:construction: *in process*) *(Leanpub account or valid email requested for EPUB or PDF)*
 * [The Go Tutorial](http://tour.golang.org)
 * [The Little Go Book](https://github.com/karlseguin/the-little-go-book) - Karl Seguin ([PDF](https://www.openmymind.net/assets/go/go.pdf), [ePUB](https://www.openmymind.net/assets/go/go.epub))