feat(derive): add option to derive serde(default) attribute

[maxjoehnk]

I really like this crate. It's great for loading multiple layers of configuration but as it wasn't possible to add the serde(default) attribute only to the derived struct I've added this flag.

[bengreenier]

thanks @maxjoehnk - sorry, just seeing this now. I'll make time to review this later today, and get it merged/an update out soon baring any issues.

[bengreenier]

@maxjoehnk could you take a look at #5 and tell me what you think? It supports this feature, but in a more generic way (so it works with other libraries that use container attributes that one might want to define on a Partial as well).

#[derive(Partial)]
#[partially(derive(Serialize, Deserialize))]
#[partially(attribute(serde(default)))]
struct Data {
  value: String
}

If that meets your needs then I will close this one out, in favor of #5 with complete credit for the idea going to you 😄

[maxjoehnk]

That looks great. I'm only on mobile right now so couldn't test it but this should solve my use case.

Imo you can close this PR and replace it with #5.

[bengreenier]

alright - that's shipped - crates.io - docs.rs

thanks for the idea/PR @maxjoehnk - closing this one out now - let me know if you have any issues!