Somehow the rustdoc heuristics determined that a large chunk of the items
found in prelude should have documentation inlined. This bloats the
generated documentation size.
Also, for crates that optimize documentation with `cfg(doc)`, as the
documentation inlining makes use of the metadata compiled by just rustc, it
will not pick up the `cfg(doc)` attributes from the inlined documentation.
pin-init for example optimizes tuple/fn rendering using the nightly
fake_variadic feature [1], but this is missing from the inlined version
[2].
Thus, mark all prelude items as `#[doc(no_inline)]`.