asciidoctor: update page and Russian translation

[trolzen]

I've also updated the original page:

1. The --attribute option requires its value to be an equal sign-separated pair.
2. In the last example, pdf and asciidoctor-pdf shouldn't be marked as placeholders.

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The page(s) follow the style guide.
• The PR contains at most 5 new pages.
• The PR title conforms to the recommended templates.

[iridacea]

Looks good to me.

[Managor]

I forgot