Missing directives in English docs

[Nginx User]

Just noticed that the "merge_slashes" core directive according to the
Russian docs is not present in the English docs.

I notice that there are always links to "original documentation" in
the english language section.

1. Are the Russian docs the actual official ones? I.E., the English
ones are just there as a convenience provision to help out those of us
that do not speak Russian but are on a "use at your own risk" basis?

2. Should I start learning Russian?

Спасибо