fix: field-attrs.md #[serde(skip)] and #[serde(skip_serializing)] content invert

[SoonIter]

No description provided.

[dtolnay]

Thanks for the PR!

I think this documentation was correct before this PR.

[dtolnay]

This is not what skip_serializing does. skip_serializing does not affect the behavior of deserialization.

[SoonIter]

Thanks for the PR!

I think this documentation was correct before this PR.

serde-rs.github.io/_src/field-attrs.md

Lines 47 to 63 in 66d53ef

	- ##### `#[serde(skip)]` {#skip}
	Skip this field: do not serialize or deserialize it.
	When deserializing, Serde will use `Default::default()` or the function
	given by `default = "..."` to get a default value for this field.
	- ##### `#[serde(skip_serializing)]` {#skip_serializing}
	Skip this field when serializing, but not when deserializing.
	- ##### `#[serde(skip_deserializing)]` {#skip_deserializing}
	Skip this field when deserializing, but not when serializing.
	When deserializing, Serde will use `Default::default()` or the function
	given by `default = "..."` to get a default value for this field.

I'm sorry, these sentences are not very neat so I think one of these three sentences is not right.
Now I know that only deserializing is a special case which needs Default::default().