[Just Merge Me] Russian Translation Update (vuejs#612)

* russian docs translation started

* docs/ru/actions.md translated

* docs/ru/api.md translated

* docs/ru/forms.md translated

* api translation fix

* docs/ru/getters.md translated

* docs/ru/getting-started.md translated

* docs/ru/hot-reload.md translated

* docs/ru/installation.md translated

* docs/ru/intro.md translated

* docs/ru/modules.md translated

* docs/ru/README.md translated

* docs/ru/strict.md translated

* docs/ru/structure.md translated

* docs/ru/SUMMARY.md translated (O_O for some reason it happens to be exactly the same as README.md)

* docs/ru/mutations.md translated

* docs/ru/plugins.md translated

* docs/ru/state.md translated

* docs/ru/testing.md translated

* docs/ru/actions.md styling/proof-reading

* docs/ru/api.md styling/proof-reading

* docs/ru/forms.md styling/proof-reading

* docs/ru/getters.md styling/proof-reading

* docs/ru/getting-started.md styling/proof-reading

* docs/ru/hot-reload.md styling/proof-reading

* docs/ru/installation.md styling/proof-reading

* docs/ru/intro.md styling/proof-reading

* docs/ru/modules.md styling/proof-reading

* docs/ru/mutations.md styling/proof-reading

* docs/ru/plugins.md styling/proof-reading

* docs/ru/state.md styling/proof-reading

* docs/ru/strict.md styling/proof-reading

* docs/ru/structure.md styling/proof-reading

* docs/ru/testing.md styling/proof-reading

* docs/ru/intro.md typo fix

* Copyediting RU documentation

* Fix typo

* Change wording around alternative approaches to data handling

* Fix typo

* Fix typo

* Better wording for linters

* Fix header and change wording

* fix typo

* typos reported by @ipelekhan are fixed

* Russian docs translation update

* Fix typo

* Sentence rephrasing and fix punctuation

Author: gbezyuk