Fastline app description: improve and cleanup and translate to Ru

[yurtpage]

Description

I changed the app description to make it more user friendly and easier to translate. To test I also added ru translation (@Ftonans please review if you are interested).

Please integrate a translation service like Weblate, Crowdwin, Transifex, Localise.com, PoEditor.com etc. That will simplify translation significantly. The Weblate and Crowdwin also allows to translate the fastlane app metadata which is also important.

Fixes: none

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [x] Code style (formatting, new lines, etc.)
• [] Refactoring (no functional changes, renaming)
• [x] Other (describe the changes):

Checklist:

• [x] My code follows the style and architecture of the project
• [x] I have performed a self-review of my code
• [ ] I have tested the app on an actual Android device and everything works as expected
• [ ] I have commented my code, particularly in hard-to-understand areas
• [x] My changes generate no new warnings or errors
• [x] New and existing tests pass locally with my changes

[mhss1]

Hi, thanks for the contribution. Please make the pr to the dev branch instead of master. Also, the app name is not translatable so you don't have to translate that