key-format-style more options

[tomas-vahala-unbiased-co-uk]

What rule do you want to change?
key-format-style
https://eslint-plugin-vue-i18n.intlify.dev/rules/key-format-style.html

Does this change cause the rule to produce more or fewer warnings?
fewer if you choose more then one key format

How will the change be implemented? (New option, new default behavior, etc.)?

"@intlify/vue-i18n/key-format-style": [
      "error",
      "camelCase" | "snake_case",
      {
        "allowArray": false,
        "splitByDots": false,
      }
    ],

or

"@intlify/vue-i18n/key-format-style": [
      "error",
      ["camelCase", "snake_case"],
      {
        "allowArray": false,
        "splitByDots": false,
      }
    ],

Please provide some example code that this change will affect:

"keyName": "value",
"key_name": "value

What does the rule currently do for this code?
It will not throw an error if you choose more than one type of key-format-style

What will the rule do after it's changed?
if you choose more options like camelCase and snake_case, it will not throw an error.

Additional context

since we are storing some of our variables, it would be great to quickly distinguish them just by the key