doc: move body of examples from near (gated under __macro_docs feature) module to #[near] macro doc (with link)

[dj8yfo]

Body of all sub-attributes/annotations docs in https://docs.rs/near-sdk/5.7.0/near_sdk/near/index.html has
to be moved to documentation of https://docs.rs/near-sdk/5.7.0/near_sdk/attr.near.html ,
and links to new place left via #anchors

using rust-lang/rust#62833

/// See [`near_sdk::near #[init]`](macro@crate::near#init-sub-attribute)

Thus individual sub-attributes/annotations will remain searchable

but the documentation for all about #[near] macro will be on https://docs.rs/near-sdk/5.7.0/near_sdk/attr.near.html page

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1. module has to be renamed from near to near_annotations as it conflicts with #[near] top item, that's why macro@crate is needed above
2. near_sdk::near_annotations::handle_result
3. near_sdk::near_annotations::init
4. near_sdk::near_annotations::payable
5. near_sdk::near_annotations::private
6. near_sdk::near_annotations::result_serializer
7. near_sdk::near_annotations::event_json (??, not present yet)
8. near_sdk::near_annotations::contract_metadata (??, not present yet)

[dj8yfo]

this in conjunction with #1288 might improve overall structure of rustdocs regarding #[near] macro,
allowing to keep it up-to-date and possibly adding other, yet undocumented sub-attributes

[dj8yfo]

this is mutually exclusive with #1287, so closing #1287