Playground settings can only be &str

[tim-maddison-rnf]

Expected Behavior

Playground settings should be able to accept any JSON type (although maybe not Object or Array?).

Actual Behavior

with_setting can only accept a &str for the value, so any values passed are serialised into a JSON string. These then stay as a string while being inserted into the playground settings.

playground_source(
      GraphQLPlaygroundConfig::new("/admin/api/graphql")
          .with_setting("schema.polling.enable", "false"),
)

Specifications

• Version: 2.9.9
• Platform: Linux

I think this could be solved by changing GraphQLPlaygroundConfig's settings Hashmap into Hashmap<&'str, Value> and then changing with_setting to accept a Value.

I'd be happy to put a PR together for this, let me know if you think this is viable.

[sunli829]

Good idea,welcome to PR.👏