How to customize laravel array validation error keys and message

I use FormRequest in my app for validating data.

Example code:

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class UserRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'skills' => "required|array",
            "skills.*" => "required|min:2|max:20"
        ];
    }
}

Here by default when I pass to request this example data:

{
    "skills" => [
        "a",
        "apple"
    ]
}

Then get error message:

{
    "errors": {
        "skills.0": [
            "The skills.0 must be at least 2 characters."
        ],

        "skills.1": [
            "The skills.1 may not be greater than 4 characters."
        ]
    }
}

How I can customize this validation error messages and get something like this errors on result:

{
    "errors": {
        "skills": [
            "The skills with key 0 must be at least 2 characters.",
            "The skills with key 1 may not be greater than 4 characters."
        ]
    }
}