Add Chuvash language layout

[flashymittens]

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Feature description

Please add Chuvash Cyrillic layout. It should likely be based on the Russian one.

Why do you want this feature?

It's my native language and I'd like to write in it.

Additional information

Alphabet: https://en.wikipedia.org/wiki/Chuvash_language#Official.

[tenextractor]

@flashymittens Here is the Gboard layout for Chuvash:

Й У Ӳ К Е Ӗ Н Г Ш З Х
Ф Ы В А Ӑ П Р О Л Д Э
Я Ч С Ҫ М И Т Ь Ю

It seems like this layout needs long presses to type a few letters (like long press В = Б). This seems inconvenient so I would like to suggest this layout instead:

Ё Ӑ Ӗ Ҫ Ӳ Ъ
Й Ц У К Е Н Г Ш Щ З Х
Ф Ы В А П Р О Л Д Ж Э
Я Ч С М И Т Ь Б Ю

Putting the extra letters on the side would probably make the keys too small and confuse the muscle memory of people who are used to the Russian layout, so I suggest this.
Which layout is better in your opinion?

[flashymittens]

@tenextractor If possible, I'd prefer the 2nd one, so all letters will be visible. Long-tapping is pretty inconvenient when done frequently.

[tenextractor]

@flashymittens

This was the layout I added, please feel free to give any suggestions or corrections.

[flashymittens]

@tenextractor Looks great to me 🙂