No public initializers for `KeyParams` and `KeysQuery` structs.

[mannuch]

Hello!

The KeyParams and KeysQuery structs do not have publicly accessible initializers. This implies that any code outside the MeiliSearch module cannot create new instances of these structs.

This works in direct contrast to examples laid out in the Meilisearch documentation such as when it displays constructing new KeyParams instances to pass to the POST /keys endpoint, which can be seen here, if you select Swift as the client language.

Thanks!

meilisearch-swift v0.14.1

[curquiza]

Hello @mannuch thanks for having opened this issue! 😄 Reviewing your PR today!