Sorting JSON alphabetically by first letter

I have a JSON like this:

[
  {
    "id": 1,
    "slug": "abakan",
    "name": "Абакан"
  },
  {
    "id": 4,
    "slug": "almetevsk",
    "name": "Альметьевск"
  },
  {
    "id": 10,
    "slug": "astrahan",
    "name": "Астрахань"
  },
  {
    "id": 11,
    "slug": "barnaul",
    "name": "Барнаул"
  },
  ...
]

And getting this by this method:

public function getCities()
{
    $cities = City::mainCities()->get(['id', 'slug', 'name']);
    return response()->json($cities);
}

How can i sort this list alphabetically and with their letters. For example:

"A": [
  {
    "id": 1,
    "slug": "abakan",
    "name": "Абакан"
  },
  {
    "id": 4,
    "slug": "almetevsk",
    "name": "Альметьевск"
  }
],
"B": [
  {
    "id": 11,
    "slug": "barnaul",
    "name": "Барнаул"
  },
  ...
]

and so on...

I have Laravel on the backend and VueJS on front.

via Chebli Mohamed