Update tech-modules.ru.md

The changes, proposed by Vova Grinenko was added.
Merge pull request #496 from Murdalay/patch-5

Updated documentation for tech modules development (rus only)
It contains Vika's contribution to the tech modules documentation.
Ragnar's version of the documentation about a tech modules.
Merge pull request #509 from Murdalay/dev

Версия документа по модулям технологий с самыми свежими правками
Merge pull request #1 from bem/dev

docs