IPv6 book by Yar Tikhiy (#3151)

* IPv6 for IPv4 Experts english has been added

* IPv6 for IPv4 Experts russian has been added

* IPv6 for IPv4 Experts russian URL change

* IPv6 for IPv4 Experts english URL change

free-programming-books-ru.md

@@ -87,6 +87,7 @@
 
 #### Работа с сетью
 
+* [IPv6 для знатоков IPv4](https://sites.google.com/site/yartikhiy/home/ipv6book) - Ярослав Тихий (PDF, HTML, EPUB)
 * [Разъяснение HTTP2](https://github.com/vlet/http2-explained/blob/master/http2.ru.pdf?raw=true) - Даниэль Штенберг (PDF)
 
 

free-programming-books.md

@@ -585,6 +585,7 @@
 * [High-Performance Browser Networking](https://hpbn.co) - Ilya Grigorik
 * [HTTP Succinctly, Syncfusion](https://www.syncfusion.com/resources/techportal/ebooks/http) (PDF, Kindle) (email address *requested*, not required)
 * [HTTP2 Explained](http://daniel.haxx.se/http2/) - Daniel Stenberg
+* [IPv6 for IPv4 Experts](https://sites.google.com/site/yartikhiy/home/ipv6book) - Yar Tikhiy (PDF)
 * [The TCP/IP Guide](http://www.tcpipguide.com/free/t_toc.htm)
 * [Understanding IP Addressing: Everything you ever wanted to know](http://pages.di.unipi.it/ricci/501302.pdf) (PDF)
 * [ZeroMQ Guide](http://zguide.zeromq.org/page%3Aall)