[LyX/master] Update ru.po and UserGuide

[Pavel Sanda]

On Fri, Nov 10, 2023 at 06:07:02PM +0100, Yuriy Skalko wrote:
> If previous versions will be left, then there will be duplicated items in
> menu since these linguistics tables "tableaux" translate just as "tables".
> So I added these "(ling.)" prefixes to distinguish them.
> 
> There is also a calque from "tableau" word, but it has different meaning and
> does not fit here.

Well I doubt that you want to have "Table (lit.)" in the latex output, but if
there is no corresponding word for tableaux in your language, then this whole
discussion is probably void anyway.

In next iteration I'll replace the strings in layouttranslation in whatever
you decide is best and is present in the .po file.

Pavel