Add Russian layout with typographic symbols
This layout is the first step to Russian-Tatar united keyboard layout described here: https://800147.github.io/rtu/en
Separate Russian-only layout is needed to make this "Russian-<other Cyrillic> united" scheme more universal. This Russian layout should become the base for those layouts.
The advantage of this layout is that it has symbols that are required for modern communication (# and @) as well as symbols required for competent writing in Russian («, », „, “, —, – etc). It is just attempt to modernise ru(winkeys).
Important detail is that I tried not to overload this layout with engineering or ancient symbols to keep most of the letters keys`s third layers free, making it easier to set <other Cyrillic> languages letters to them. For example, letter "Ң" in the third layer of "Н".